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Date
Jun
07
2006

Weather Conditions and Disparities in Physical Activity and Obesity in the United States

Presenter:

Daniel Eisenberg

Authors:

Daniel Eisenberg, Edward Okeke

Chair: Michael Hagan; Discussant: Chad Meyerhoefer Wed June 7, 2006 9:45-11:15 Room 121

Context: The adult obesity rate in the U.S. is now over 30 percent. Exercise has been shown to be an effective weight control device in carefully controlled randomized trials, but it is less clear whether interventions designed to encourage exercise are effective in real-world community settings. One environmental factor that may be important in real-world settings is the weather. Little is known about how sensitive exercise participation rates are to outdoor weather conditions. For many people, particularly those in lower socioeconomic status (SES) groups, perceived exercise options may become very limited during unpleasant (unusually hot, cold, or wet) weather. Information regarding the relationship between weather conditions, exercise, and obesity across SES groups would be valuable for policymakers, community planners, health professionals, and ordinary citizens.

Objectives: We analyze the effect of weather conditions on exercise participation and the effect of exercise participation on body weight.

Statistical Methods: We employ linear regression models, including models with year, state, and state*month fixed effects, to test how exercise participation responds to unusual weather conditions. We then employ a two-stage instrumental variable (IV) model to test the causal effect of exercise on body weight, with weather conditions serving as IVs for exercise.

Data: We examine nationally representative data from the Behavioral Risk Factor Surveillance System (BRFSS) during 1993-2001 in the United States (total N = approximately 1.5 million). Individual level BRFSS data include measures of body mass index (BMI), exercise activities, diet, and socioeconomic and demographic characteristics. Using interview dates in BRFSS, we link these data to recent local weather conditions, available from the National Climatic Data Center.

Results: Our analysis is ongoing. Preliminary results suggest a strong first stage relationship between weather conditions and physical activity.

Discussion: The results of this study will help inform current public health efforts to increase exercise and reduce obesity. We will improve understanding of whether interventions must account for the diverse weather conditions in this country across regions and the seasons, and whether such interventions should focus on certain SES groups.

Cost Effectiveness of Interventions for Teen Diet and Exercise

Presenter:

Marilyn Frenn

Authors:

Marilyn Frenn, Evelyn Kuhn, Hua Liu, Ramesh Sachdeva

Chair: Michael Hagan; Discussant: Michael Hagan Wed June 7, 2006 9:45-11:15 Room 121

PURPOSE: To test the effectiveness of a school-based intervention on dietary fat intake and physical activity, determine which intervention was more effective in reducing dietary fat and increasing physical activity in middle school youth, and to assess the cost of each intervention in relation to effectiveness.

BACKGROUND: Obesity in children results in many health problems during childhood and later in life. Healthy People 2010 goals include reducing overweight among adolescents aged 12-19 through sound dietary practices and increased physical activity. African Americans, Hispanics, Native Americans and children from low-income families in any race are most at risk for obesity and associated health problems. Project FUN was developed using the Health Promotion/Transtheoretical Model to tailor computerized interventions. Tailored interventions, used in the computerized model, modify feedback based on characteristics previously demonstrated to improve nutrition and exercise behaviors. Individualized interventions, used in the Email model, modify feedback based on many characteristics evident in clients. The third model utilized peers to provide group support for healthy behaviors.

METHODS: Culturally diverse, low-middle income, 6th and 7th grade youth (N=447) were assigned by classroom to the control or one of the three intervention groups to avoid diffusion of the interventions to the control condition. The first intervention group received education from a computerized model, the second group had the computerized model plus Emailed feedback, and the third group had the computerized model plus access to peer feedback. Trained nursing students gave individual Emailed responses to students’ answers to questions posted to a discussion board. The peers were trained with three additional computer modules and a _ day session on campus to provide support for improved diet and exercise behaviors in their class. Costs of intervention were calculated for each intervention group. The outcome variables were percentage dietary fat and physical activity measured by exercise log.

RESULTS: Costs for computerized model alone, were $39.89 per student. For computerized model plus Email feedback the costs were $53.12. And finally, computerized model plus peer feedback costs were $73.40. General Linear Model demonstrated a difference among groups for reducing dietary fat (p<0.037) with Email being the most effective, followed by peer feedback. Changes in physical activity showed significant interactions with gender (p=0.042), grade (p=0.036), and with gender, grade, and race (p=0.046) again with the Email approach being most effective. Computerized model and computerized model plus peer feedback approaches were effective for some, but not all subgroups.

CONCLUSION: Although computerized interventions were least expensive, those assisted by individualized Email most effectively decreased dietary fat intake and increased physical activity behaviors among middle school youth. Further refinement of the computer-tailored tool, based on gender, race, and grade, may improve its effectiveness.

The Effect of Physical Activity on Short Run Medical Costs and Lost Work Days among US Adults

Presenter:

Eric Keuffel

Authors:

Eric Keuffel

Chair: Michael Hagan; Discussant: Michael Hagan Wed June 7, 2006 9:45-11:15 Room 121

Author: Eric Keuffel (ekeuffel@wharton.upenn.edu), Wharton, University of Pennsylvania.

Title: The Effect of Physical Activity on Short Run Medical Costs and Lost Work Days among US Adults

Background: Regular physical activity is frequently defined as rigorous activity sustained for at least 30 minutes three times per week. While the epidemiological implications of regular physical activity are well-established, the association between activity level and economic medical costs is not as well understood in US adults. The incentives for offering effective primary prevention programs promoting physical activity are influenced by anticipated cost savings and work days saved. Given the high rate of managed care and employee turnover in the US, short run returns are particularly important. Prior studies offer varying conclusions; some find short-run returns to physical activity others find no effect.

Objective: This study estimates the effect of regular physical activity on medical costs and days work lost after accounting for demographics, medical conditions, health insurance status and other covariates. I examine whether current year physical activity, prior year physical activity and persistent two-year physical activity result in lower medical costs and work days lost.

Data: The study data are from the 2001-2002 Medical Expenditure Panel Survey (MEPS). There are 15,269 adults (> age 16) in panel six of MEPS with data recorded in both years. MEPS records physical activity with a bivariate measure (1-rigourous physical activity at least 3 times per week/30 minutes per session; 0-not physically active) for both 2001 and 2002.

Methods: Year 2002 medical costs are modeled with a two part approach using STATA 9.1. Part I uses a probit regression to estimate the probability of positive costs. Part II estimates total medical costs conditional on positive costs with a generalized linear model (GLM gamma). Marginal effects accounting for both stages were estimated. A negative binomial model estimated the percent change in work days associated with physical activity. In each case, three separate specifications test whether current year physical activity (2002), prior year physical activity (2001) or persistent physical activity (2001 and 2002) significantly effect costs or days work missed. The base case uses robust standard errors and clusters on household.

Results: Mean 2002 medical costs in the sample are $3,025 (SD=$8,207) and 18 percent of the sample have no costs. After controlling for covariates; current, prior and persistent physical activity significantly increases (p<.10) the probability having positive costs, but only by 0.8 -1.1 percent. Physical activity is associated with lower conditional costs. Overall, point estimates for the marginal effects of current and prior year physical activity were -$32 and -$203, respectively. Mean days of work missed due to illness were 4.7 (SD=15.3 n=8,661). Persistent physical activity results in 17% fewer days missed due to sickness (p<.01).

Conclusions: Returns to physical activity in terms of medical costs are relatively modest over two years and most of the returns appear to accrue as a result of activity in the first year. Missed work days are a potentially important component when calculating the benefits of physical activity.

Are there differential effects of Medicaid and SCHIP managed care on children with chronic conditions?

Presenter:

Amy Davidoff

Authors:

Amy Davidoff, Brigette Courtot, Emerald Adams

Chair: Ciaran Phibbs; Discussant: Ciaran Phibbs Wed June 7, 2006 9:45-11:15 Room 213

Rationale: Results of recent studies examining effects of Medicaid managed care have been mixed, with various studies reporting small reductions in ER use and hospitalizations, and increases in outpatient visits. The effects of managed care may be particularly strong for children with chronic health conditions, for whom managed care organizations have strong incentives to manage care and control costs. Alternatively, baseline use by these children may be appropriate, and managed care may exert its effects by disrupting established provider relationships. The use of behavioral health or specialty carveouts to capitated plans may further interfere with care coordination.

Objectives: To examine effects of different types of mandatory managed care programs, including use of carveouts, on children with and without chronic health conditions enrolled in Medicaid or SCHIP .

Methodology: Data on child characteristics, health status, and access and use of healthcare services are from pooled National Health Interview Survey data (1997-2002.) Data on Medicaid and SCHIP managed care program types, areas served, populations covered, and use of carve outs were collected from annual CMS Medicaid Managed Care Enrollment Reports, state specific SCHIP plans, and an Urban Institute survey of managed care implementation. A county and year specific database was created on type of managed care and whether enrollment was mandatory for children generally, and for SSI recipients or other children with chronic conditions. Managed care data were linked to children eligible for Medicaid or SCHIP, with program specific eligibility determined by application of state and year specific eligibility rules. Linear probability models were estimated for all publicly insured children, with a vector of managed care program types, child health status, and interactions between them, with controls for child, family, area characteristics, state and year.

Results: For children without chronic conditions, few managed care plan effects were significant relative to FFS. Mandatory capitated or mixed PCCM/capitated programs were associated with increased likelihood of using prescription medication. In contrast, for children with chronic conditions, mandatory PCCM and mixed mandatory PCCM/capitated programs without carve outs were associated with fewer physician visits, any specialist visits, ER use, hospital stays, and prescription drug use. When carveouts were present, effect sizes were smaller, and only the negative effects on physician visits, specialist visits and prescription drug use were significant.

Conclusions: Although managed care delivery systems may affect perceived access and use of preventive and acute services for generally healthy children, the results of this analysis suggest that the effects operate primarily on children with chronic health conditions. Mandatory enrollment in managed care, both PCCM and capitated plans, was associated with reductions in use of a variety of services. It is not possible to tell whether these changes resulted in more appropriate use of services. However, we did not observe a corresponding increase in reported unmet need for medical care or prescription drugs, thus, the net change may represent an improvement in care. Additional focus on quality and appropriateness effects of managed care on children with chronic conditions is warranted.

Effects of the State Children's Health Insurance Program (SCHIP) on Access to Dental Care and Use of Dental Services

Presenter:

Hua Wang

Authors:

Hua Wang, Edward Norton, Gary Rozier

Chair: Ciaran Phibbs; Discussant: Gabriel Picone Wed June 7, 2006 9:45-11:15 Room 213

Rationale: Lack of dental insurance is one of the main barriers to access to dental care for many low-income children in the U.S. The State Children’s Health Insurance Program (SCHIP), created by Congress in 1997, expands eligibility for public dental insurance to uninsured low-income children in almost all states. SCHIP may have extensive influence because it is also designed to facilitate Medicaid enrollment and it gives states flexibility in experimenting with new models that may overcome historical obstacles to access to dental care in public programs. Yet the extent to which SCHIP has improved children’s access to and use of dental services is largely unknown, especially at the national level.

Objective: To provide national estimates of the total implementation effects of SCHIP on dental care access and use for low-income children.

Methodology: Two separate analyses are conducted to estimate (1) the effect of program availability on dental care access and use for low-income children (regardless of eligibility or enrollment); and (2) more specifically, changes in dental care access and use for children who gained public insurance as a result of SCHIP implementation. In the first analysis, we consider SCHIP implementation a natural experiment, which has considerable variation in the timing of program implementation across states. We use the variation to identify the effect of SCHIP availability on dental care access (unmet need for dental care due to cost in the past year) and dental services use (time since last dental visit) for any low-income (<300% Federal Poverty Level) child in county and time fixed effects models. In the second analysis, we employ the instrumental variables method to “identify” children who had public insurance due to SCHIP implementation in addition to deal with endogeneity of insurance. State-level SCHIP program features are selected as instruments for public coverage, including program availability, eligibility thresholds, and waiting periods. By focusing on SCHIP’s overall effects, both analyses avoid the difficulty of imputing program eligibility or misreporting of SCHIP enrollment in the data. Both analyses estimate linear probability models adjusted for survey designs. The data source is the National Health Interview Survey 1997-2002 (N = 40,000+).

Results: SCHIP availability for more than one year reduced the likelihood of experiencing unmet dental care need for any low-income child by 2.8 percentage point; increased the probability of having a dental visit within 6 months or in the past 6-12 months by 2.2 and 0.9 percentage point, respectively. Compared with their uninsured counterparts, those who obtained public coverage from SCHIP implementation were less likely to report unmet need for dental care by 11.6 percentage point, and more likely to have visited a dentist within 6 months or in the past 6-12 months by 31 and 35.7 percentage point, respectively. School-aged children (6-17 years) fared better than younger children. Type of SCHIP program had no differential effects.

Conclusions: Consistent results from two analytical approaches provide solid evidence that SCHIP implementation has significantly reduced financial barriers to dental care and increased use of dental services for low-income children in the U.S.

The Role of Race and Ethnicity in Children's Health Insurance Coverage

Presenter:

Thomas Selden

Authors:

Thomas Selden, Yuriy Pylypchuk,

Chair: Ciaran Phibbs; Discussant: Kosali Simon Wed June 7, 2006 9:45-11:15 Room 213

The Role of Race and Ethnicity in Children’s Health Insurance Coverage: A Decomposition Analysis Using the Medical Expenditure Panel Survey

Large racial and ethnic disparities exist with respect to the insurance of children. In 2002, 77 percent of white (non-Hispanic) children age 0-18 had private coverage during the year, versus only 41% of Hispanic children and 47% of non-Hispanic black children. For non-Hispanic black children, this gap is closed by far higher rates of public coverage: 48% versus 17% among white children. Among Hispanic children public coverage fails to close the gap, and the prevalence of full-year uninsurance at 15% is more than twice the average of all other children.

What explains these large disparities? In this paper, we pool data from the 2000-2002 Medical Expenditure Panel Survey (MEPS) to implement Oaxaca-Blinder decomposition analysis. Pooling yields a sample of nearly 30,000 observations. Factors considered include age, sex, geographic location, family composition, family poverty, parent education, parent employment, the nativity and citizenship of children and their parents, and the language used to administer the survey. Because having a parent who is eligible for employment-related insurance is a key factor in children obtaining private insurance, we also conduct a decomposition analysis of disparities in parent eligibility rates and child take-up rates.

Whereas Oaxaca-Blinder decomposition was developed for the analysis of continuous dependent variables, the dependent variables in our analysis are discrete. This raises issues regarding econometric specification. We implement two solutions. The first is simply to apply Oaxaca-Blinder methods to linear probability regressions. The second is to decompose estimates from a multinomial logit model (MNL). MNL decomposition is a recently-developed technique that requires matching of children across groups. We explore a range of strategies for matching, including a method we develop that more flexibly incorporates sample weighting schemes applicable to most household survey data.

Perhaps not surprisingly, the key determinant of racial and ethnic coverage disparities among children is poverty. Secondary, but nevertheless important, factors include citizenship, language, parent education, and Census division. Together, the factors we examine explain nearly 80 percent of the racial and ethnic coverage disparities in our sample.

A Multi-linear Multi-Attribute Utility Function for the Health Utilities Index Mark 3 System

Presenter:

David Feeny

Authors:

David Feeny, William Furlong, George Torrance, Charles Goldsmith, Sonja DePauw, JoAnn Kingston-Riechers

Chair: Albert Okunade; Discussant: Albert Okunade Wed June 7, 2006 9:45-11:15 Room 225

Rationale and Objectives. Estimated multi-attribute utility functions have relied on linear additive or multiplicative functional forms that assume respectively a lack of preference interactions among attributes or only one type of preference interaction. Are there quantitatively important and statistically significant interactions in preferences among attributes in the Health Utilities Index Mark 3 (HUI3) system? How would the performance of the less restrictive multi-linear model compare to the performance of the multiplicative model?

Methodology. HUI3 has 8 attributes, vision, hearing, speech, ambulation, dexterity, emotion, cognition, and pain, with 5 or 6 levels per attribute. A preference survey was conducted of a random sample of the general population (n = 256) using a one-half 2 to the eight power fractional factorial design plan. The same survey provided scores for the estimation of a multiplicative multi-attribute utility function. A parallel survey (n = 248) provided directly measured standard gamble utility scores for 73 HUI3 health states. The fractional factorial design permits the identification of all 8 main effects, 26 of 28 two-way interactions, and 4 of 56 three-way interactions terms. The estimated equation was forced to pass through 0 (for the health state with all attributes at lowest functional level) and 1 (all attributes at highest level). Agreement between directly measured scores from the second sample and scores from the multi-linear and multiplicative utility functions was assessed using an intra-class correlation coefficient.

Results. For the multi-linear model, the adjusted R-squared was 0.63. All 8 main effects were quantitatively important (coefficient >0.024) and statistically significant (p < 0.10). Two-way interaction terms indicating preference complementarity were quantitatively important and statistically significant in 18 cases and insignificant in 2 cases. Two-way interaction terms indicating preference substitutes were important and significant in 4 cases and insignificant in 2 cases. All 4 three-way interaction terms were important and significant. Agreement between directly measured scores and scores from the multiplicative function was much higher than agreement between directly measured scores and scores from the multi-linear function.

Conclusions. There are quantitatively important and statistically significant interactions in preferences among attributes of health status. These results call into question the use of linear additive multi-attribute utility functions. The multiplicative function out performed the multi-linear function in out-of-sample prediction. The omnibus interaction term of the multiplicative function indicates preference complementarity and appears to handle the preference interactions more than adequately.

Construct Validity of the Health Utilities Index Mark 3 (HUI3): Alzheimer Disease, Arthritis and Cataract

Presenter:

Keiko Asakawa

Authors:

Keiko Asakawa, David Feeny

Chair: Albert Okunade; Discussant: Albert Okunade Wed June 7, 2006 9:45-11:15 Room 225

BACKGROUND: HUI3 is a prominent measure of health-related quality of life (HRQL) widely used in population health surveys, clinical studies and cost-utility analyses. HUI3 includes 8 attributes (vision, hearing, speech, ambulation, dexterity, emotion, cognition and pain), with 5 or 6 levels for each attribute. HUI3 has been used to assess health status in a number of chronic conditions. However, many of these analyses are based on samples that may not be representative of the entire population and there is little evidence for some important chronic conditions.

AIM: To assess the population-health construct validity of the HUI3 system in people with Alzheimer disease (AD), arthritis (AR) and cataract (CA), all three of which are conditions prevalent among the elderly.

METHODS: 1996/97 Canadian National Population Health Survey community and institutions cross-sectional Microdata files were used for the analyses. Data for those aged 40 and over were analyzed. Overall and single-attribute HUI3 scores for the 5 groups were compared to assess construct validity: AD only, AR only, CA only, AACA (at least two of the three conditions), and REF (none of the three conditions). Community and institutional population were analyzed separately. A total of 18 multiple linear regressions, 9 each for community (sample size is approximately 36,000) and institutional (sample size is approximately 1,100) data, were conducted to estimate effects of AD, AR and/or CA on overall and single-attribute utility scores. In all models, analyses controlled for individual characteristics, socio-economic status, health risk factors and the number of co-morbidities. A total of 76 a priori hypotheses, 38 each for community and institutional samples, were specified; adjusted-mean differences among 5 groups were obtained from each equation for hypothesis testing. For HUI3, differences of 0.03 (0.05) or more in overall (single-attribute) utility scores are interpreted as clearly clinically important. To take account of the complex survey design, bootstrap and Taylor linearization methods were used for variance estimations for community and institutional data, respectively. Statistical analyses were conducted using SUDAAN 9.0.1 and SAS 9.0.

RESULTS: For community and institutional samples, 23 and 28 hypothesis tests were consistent with a priori hypotheses, respectively. In both community and institutional samples, overall scores were lower for those with AD, AR and/or CA than for reference group; cognition scores were lower for AD than those for other groups; pain scores for AR were lower than those for other groups. Speech scores were lower for AD than for others residing in institutions. Adjusted-mean differences were all statistically significant (p<0.05) and clinically important. Consistent with our expectations, there was no statistically significant (at 5%) and clinically important difference in mean hearing scores among the 5 groups.

CONCLUSIONS: HUI3 was able to discriminate various aspects of burden associated with AD, AR and CA in both community and institutional samples. HUI3 was able to describe differences in overall HRQL levels as well as burden associated with vision, speech, cognition and pain. HUI3 is useful in assessing HRQL of AD, AR and CA for those in the community and in institutions.

Consistency between willingness to pay for reducing the risk of adverse drug events and the associated health-related utility gain

Presenter:

Rosa Rodriguez-Monguio

Authors:

Rosa Rodriguez-Monguio

Chair: Albert Okunade; Discussant: Albert Okunade Wed June 7, 2006 9:45-11:15 Room 225

Rationale: Adverse drug events (ADE) have an impact on health utility, and individuals are willing to pay to reduce the risk of suffering such events. Objectives: The objective of this study is to assess the consistency between the willingness to pay (WTP) for reducing the risk of adverse drug events and the associated health-related utility gain. The study quantifies the monetary value of reducing the risk of incidence of mild ADE and measure the health-related utility gain for such a reduction.

Methodology: Personal interviews were completed for 174 people in Madrid (Spain). Upon definition of a payment card, individuals were asked for the amount of money they would be willing to pay to reduce the risk of incidence of ADE. Using Standard Gamble, individuals were also asked for the health-related utility gain they would derive from a reduction in the probability (p) of occurrence of ADE. Consistency among the preference relation, the willingness to pay (WTP) to reduce the risk of ADE and the health-related utility gains was assessed. Consistency between the WTP for different risk reductions and the level of risk reduction of the same ADE was also evaluated.

Results: Gastrointestinal distress and heartburn (GI) was ranked as less preferred than skin rash (SR) by 99.4% of interviewees. Interviewees were willing to pay annually an average of 379.51_ to avoid GI (CI 325.40_ - 433.62) and 148.40 (CI 118.58_ - 178.22) to avoid SR. Interviewees were willing to pay 223.49 (CI 187.34_ - 259.64) for an 80% GI risk reduction, and 79.37 (CI 57.20_ - 101.55) for an 80% SR risk reduction. Interviewees were willing to pay 162.45 (CI 128.94_ - 195.96) for a 50% GI risk reduction and 49.25 (CI 30.47_ - 68.03_) for a 50% SR risk reduction. Interviewees considered the health-related utility gain (1-p) derived from the avoidance of GI 0.67 (CI 0.28- 0.35) higher than the health-related utility gain attributed to the avoidance of SR 0.09 (CI 0.07- 0.12). The WTP and the stated health-related utility were consistent for SR (Pearson correlation coefficient = -0.283, p-value <0.01). The Pearson correlation coefficient was not statistically significant in the case of GI.

Conclusions: The willingness to pay amount was consistent with the stated preference relation, and it was also consistent for different levels of risk reduction in the incidence of ADE. The willingness to pay was not proportional to the size of the risk reduction. The value of a health gain may differs depending on the method applied for each assessment.

A study of income-motivated behavior among general practitioners

Presenter:

Tor Iversen

Authors:

Tor Iversen

Chair: Melayne McInnes; Discussant: Melayne McInnes Wed June 7, 2006 9:45-11:15 Room 226

Background: Regulated fee-for-service payment is likely to result in excessive number of services under monopolistic competition in the physician market. On the other hand, pure capitation payment is likely to result in underprovision of services. Hence, optimal payment systems for physicians are likely to be a mix of several components. We study the effect of a mixed capitation and fee-for-service system on the amount of services provided by physicians. In particular, we study to what extent the variation in service intensity among general practitioners (GPs) may be explained by an observation that some physicians have fewer regular patients than they would like to have (they experience a shortage of patients), combined with fee-for-service payment. If physicians, who experience a patient shortage, increase their intensity of service provision as a means to increase their income, we call it income-motivated behavior.

Theory: By means of non-linear programming a GP’s optimal practice style (described by the length of his list of patients and the level of service intensity) is derived under a mix of capitation and fee for service. We find that a GP, who experiences a shortage of patients, is likely to increase the number of services he provides to his patients if the marginal utility of leisure is less than the marginal utility of income from the extra services.

Empirical strategy: The sample consists of all GPs (3650) in the nationwide list patient system in Norway. Panel data at the level of individual GPs are available for the period 2001-2004. With panel data, unobserved heterogeneity is likely to occur. The assumptions of ordinary least squares regression are then violated since errors terms of different periods are correlated. We also suspect that patient shortage is not a random event. Unobserved heterogeneity is handled by generalized least squares estimation. Self selection is adjusted for by means of a Difference-in-differences estimator.

Results: We find that patient shortage increases a GP’s intensity of service provision (in particular the length of each visit) and hence, the income per listed person with 10 - 15 per cent. We also find that a GP’s income per listed person is influenced by the composition of the list according to indicators of need for services, and of accessibility according to the GP density in the municipality. These results are also valid when possible selection bias is accounted for, although the magnitude of the effects is then somewhat smaller.

Conclusion: Patient shortage is costly to the insurer because of income-motivated behavior related to the fee-for-service component of the payment system. An alternative would be to drop the fee-for-service component and let the payment system be based on the capitation fee only. But under capitation payment (with imperfect risk adjustment) not all patients are equally attractive because of variation in need for services. The present study may therefore demonstrate the classical trade off between selection and inefficiency in health care. We roughly calculate the cost of avoiding patient selection to be 3.3 % of total fee-for-service paid by the National Insurance.

Factors Affecting Physician Productivity in a Proceduralist Specialty, Radiology

Presenter:

Cristian Meghea

Authors:

Jonathan Sunshine, Cristian Meghea

Chair: Melayne McInnes; Discussant: Melayne McInnes Wed June 7, 2006 9:45-11:15 Room 226

Rationale: There is only a small literature on the production function of physicians. We add to this literature, making a number of new contributions, methodological and substantive. Curtailing health expenses is a recurrent concern in almost all developed nations, and identifying methods to improve productivity may help ease the problem. Also, with a shortage of specialist physicians believed to be impending, finding means to enhance productivity is critical to good patient care.

Objectives: To empirically investigate the determinants of productivity of radiology practices, exploring the effect of physician labor input, physician characteristics, purportedly productivity-enhancing technologies and techniques, and other practice characteristics.

  • We measure the productivity of the physician group, the production unit of medical services, while the focus of the previous literature was the individual physician.
  • This study examines the effect of technology, unlike previous work.
  • We account for the measurement error generally present in inputs data.
  • This is the first study of a procedure-centered medical specialty. Previous literature focused on physician visits.
  • We control for case mix in more detail than previous studies.

Data and Methods: Data are from the American College of Radiology’s (ACR’s) 2003 Survey of Radiologists, a nationally representative sample survey of radiologists in the United States containing information on both the respondents and the practice in which they work. We estimate the production function via OLS, the outcome being the logarithm of practice’s procedures per year. For flexibility, the physician labor inputs — full-time equivalent (FTE) radiologists, weekly hours, weeks worked annually — enter in both linear and logarithmic forms allowing for the possibility of non-constant input elasticities. To address the downward bias introduced by measurement error in labor inputs, we made various estimates of the error size and then used Monte Carlo methods to find what true elasticity combined with each plausible estimate of measurement error yields the elasticity observed in the regression.

Results: The FTE-radiologists elasticity of output is 0.8 directly measured (true elasticity between 0.85-0.90 if accounting for bias), the weekly hours elasticity is 0.4 (0.5-0.7, bias accounted) and the annual weeks elasticity is 0.4 (0.5-0.7, bias accounted). Only three of eight techniques used in radiology practices have a positive independent impact on productivity. Surprisingly, practices where individual radiologists work in more locations have higher productivity. Government owned practices are 18 percent less productive than practices owned solely by members. Practices in the Northeast and West census regions are more productive than practices in the South.

Conclusions: Due to unaccounted measurement error, previous studies probably underestimated the input elasticities in the production function of medical services. To increase output it is more efficient to add radiologists to the practice than to increase the hours or weeks worked. Some techniques used to improve radiologist productivity have less than the generally believed effect.

Nobody does it better? The impact of surgeon specialty on outcomes for carotid endarterectomy.

Presenter:

Christopher Hollenbeak

Authors:

Christopher Hollenbeak, Adam Bowman, David Han

Chair: Melayne McInnes; Discussant: Melayne McInnes Wed June 7, 2006 9:45-11:15 Room 226

Rationale: Carotid endarterectomy (CEA) is a surgical procedure that is used as a prophylaxis for stroke. It is one of the most frequently performed surgical procedures in the United States. Traditionally, this procedure has been performed by surgeons in at least four specialties: vascular surgery, cardiothoracic surgery, general surgery, and neurosurgery. Although a few studies address the effect of surgeon specialty on outcomes, these studies have focused on inpatient mortality, which is not a common outcome, and no study has examined the impact of surgical specialty on long-term rates of stroke and other cerebrovascular events that the procedure is given to prevent.

Objectives: The purpose of this study was to determine whether surgeon specialty was associated with long-term outcomes of patients undergoing CEA in Pennsylvania.

Methodology: Data were from the Pennsylvania Health Care Cost Containment Council (PHC4) and included 17,635 patients admitted for CEA between 1995 and 1997. Long term outcomes were taken from patient readmission data for the 5-year follow-up period ending in 2002. The primary outcomes studied were mortality, stroke, combined stroke and mortality, transient ischemic attack (TIA), and re-occlusion of the ipsilateral artery. Time to event for these outcomes was modeled using a Cox proportional hazards model. Secondary outcomes included length of stay and total charges. These were modeled using a generalized linear model assuming a gamma family and a log link function.

Results: Using general surgeon as the reference group, and controlling for age, race, severity, and admission type, we found no significant difference across surgical specialties in overall mortality at 5 years after CEA. Patients treated by vascular surgeons were found to have significantly fewer (P=.005) strokes at 5 years than those treated by general surgeons. Patients of cardiothoracic (P=.085) and neurosurgeons (P=.969) did not have significantly fewer strokes than those treated by general surgeons. We found no significant difference across surgeon specialties for combined 5 year stroke and death rate. Patients of vascular surgeons had fewer TIAs than those of general surgeons (P=.041) at 5 years. Patients treated by cardiothoracic (P=.508) and neurosurgeons (P=.890) did not have significantly different 5 year TIA rates from those treated by general surgeons. Finally, patients of vascular surgeons were found to have a significantly lower re-occlusion rate (P=.009) when compared to patients of general surgeons. Patients of cardiothoracic (P=.247) and neurosurgeons (P=.284) did not have a significantly different re-occlusion rate than those treated by general surgeons.

Conclusions: These results suggest that there are significant differences in outcomes for carotid endarterectomy associated with the training of the operating surgeon. One explanation for this is the human capital differences that are fostered by the surgical specialties. There may also be learning-by-doing dimensions as surgeons who perform operations on vessels and on the neck may have an advantage in terms of outcomes.

Employment-Contingent Health Insurance, Illness, and Labor Supply: Evidence from Married Women with Breast Cancer

Presenter:

Zhehui Luo

Authors:

Cathy Bradley, David Neumark, Zhehui Luo, Heather Bednarek

Chair: Timothy McBride; Discussant: TBA Wed June 7, 2006 9:45-11:15 Room 235

For the majority of non-elderly Americans, health insurance is either contingent upon their own employment or dependent upon the employment of a family member such as a spouse or parent. Past research has examined the labor supply behavior of individuals who have employment-contingent health insurance and of individuals dependent upon another’s policy. The effects of health on labor supply have also been studied. Absent from this literature, however, is an assessment of how the two-health and employment-contingent health insurance-interact to alter labor supply after an adverse health shock is experienced by an otherwise healthy employed individual. Such information would help policy makers understand some of the incentives and possible pitfalls of employment-contingent health insurance following illness. Women newly diagnosed with breast cancer were identified, shortly after diagnosis, from the Metropolitan Detroit Cancer Surveillance System (MDCSS), a population-based registry. Study eligibility criteria were age range of 30 to 64, English-speaking, and either employed or with an employed spouse at the time of diagnosis. We selected from this sample only women who were married and who were employed in the period just before diagnosis with cancer, and who were either insured through their own employer or through their spouse’s employer. Our empirical analysis of health, health insurance, and labor supply led to a clear finding that a negative health shock, as reflected in a diagnosis of breast cancer, decreases labor supply to a greater extent among women insured by their spouse’s health insurance policy than among women with health insurance through their employer. Moreover, the difference in responses associated with source of health insurance is greater for women with advanced-stage diseases-suggesting that even women who required aggressive treatment were sensitive to employment-contingent health insurance (ECHI) in making their labor supply decisions in the post-diagnosis period. We assessed whether women with ECHI were more attached to their jobs or had more desirable jobs. What we see is that there are only small and insignificant differences between those with insurance through the spouse, who were or were not offered ECHI. These results suggest, again, that the key difference is whether or not health insurance is contingent on employment, rather than job characteristics that might be associated with ECHI. The evidence from this analysis provided additional confidence in a causal interpretation of the findings rather than one attributable to selection. Employment-contingent insurance appears to be an incentive to remain working and to work at a greater intensity when faced with an adverse health shock. To our knowledge, this is the first study to prospectively and longitudinally examine how the labor supply responses of individuals experiencing a health shock depend on the source of health insurance. The findings underscore the labor supply incentives posed by ECHI. There may be potential benefits to employers from creating an incentive for employees to remain working after a health shock. However, the principal effect may be a health toll on individuals who remain working because of the incentives posed by their health insurance.

Adverse selection in a voluntary-based RMHC insurance scheme

Presenter:

Hong Wang

Authors:

Hong Wang, Licheng Zhang, Winnie Yip, William Hsiao

Chair: Timothy McBride; Discussant: TBA Wed June 7, 2006 9:45-11:15 Room 235

This study examines adverse selection in a subsidized voluntary-based health insurance, the Rural Mutual Health Care (RMHC), in the poor rural area of China. This study was made possible by a unique longitudinal data set, which combines the measures of health status and other socio-economic and demographics variables from baseline survey (before RMHC is established) with the measures of enrollment status from first year evaluation survey (after RMHC is implemented one year) from the RMHC, which is a social experimental project in rural China. Total sample of this study includes 3492 rural residents from1020 households. Multinomial Logit model is employed for the data analysis.

The results of this study show that 70% rural residents enrolled in RMHC scheme. In general, enrolled individuals have worse health status than non-enrolled health status. Although household is set as the enrolment unit for the RMHC for the purpose of reducing adverse selection, nearly 1/3 enrolled household is partial-enrolled household. The residents in the group of non-enrolled individuals in partial-enrolled households have the best health status, while the residents in the group of enrolled individuals in partial-enrolled households have the worst health status. The residents in the group of non-enrolled individuals in non-enrolled households have the second best health status, while the residents in the group of enrolled individuals in full-enrolled households have the second worst health status. Pre-RMHC medical expenditure for enrolled individual in partial-enrolled households is 206.6 Yuan per capita per year, which is 1.7 times as much as the pre-RMHC medical expenditure for non-enrolled individual in partial-enrolled households. The study also reveals that pre-enrolled medical expenditure per capita per year of enrolled individuals is 9.6% higher than pre-enrolled medical expenditure of overall residents, including both enrolled and non-enrolled individuals.

In conclusion, although RMHC scheme reached a very high enrollment rate, adverse selection still exists, especially within the partial-enrolled households. Voluntary-based RMHC would not be financially sustainable if the adverse selection were not fully taken into account.

Does Extending Health Insurance Coverage to the Uninsured Improve Population Health Outcomes?

Presenter:

Jennifer Rice

Authors:

Jennifer Rice, James Thornton

Chair: Timothy McBride; Discussant: TBA Wed June 7, 2006 9:45-11:15 Room 235

The large number of Americans without health insurance has produced a vigorous debate about whether the U.S. should adopt universal health insurance coverage. To assess whether extending health insurance coverage to a larger segment of the population is socially beneficial, it is necessary to measure the associated benefits and costs. Measuring the benefits requires a good estimate of the contribution of health insurance to measures of population health. Prior research suggests that uninsured individuals tend to have worse health outcomes than the insured; however, establishing a causal relationship and obtaining a reliable estimate of the causal effect has been difficult. In general, previous research has not adequately controlled for confounding factors associated with both health insurance coverage and health outcomes resulting in potential omitted variable bias. Many studies have also failed to account for possible reverse causation from health status to insurance coverage leading to simultaneity bias. Moreover, past research provides no information on the dynamics of the process by which changes in health insurance coverage affect mortality over time.

The objective of this paper is to investigate the aggregate relationship between health insurance and health outcomes for the general U.S. population, and extend previous work in this area in an attempt to obtain a more reliable estimate of the effect of insurance coverage on mortality that is largely purged of the influence of non-insurance determinants of health, and reverse causation. Our study addresses the following questions. Does increased insurance coverage lead to improved mortality outcomes in aggregate populations, and if so what is the size of the effect? Do different types of health insurance, such as employment, non-employment, and government financed insurance have different effects on mortality outcomes? What is the time path of the effect of insurance coverage on health outcomes? Specifically, does extending health insurance coverage to the uninsured affect aggregate health outcomes both contemporaneously and with a lag, and if so what is the size of the short-term and longer term effects?

The approach adopted in this investigation uses a panel of aggregate data on all 50 states for the period 1987-2003 to estimate a health insurance augmented, aggregate health production function for the U.S. Instrumental variable, fixed-effects, static and dynamic models are estimated that control for unobserved state heterogeneity and reverse causation. State-specific time trends are also included to allow unobservable determinants of health to vary within states over time. The effect of health insurance on mortality is therefore identified by relative within-state variation in insurance coverage. In addition, a number of observed covariates, such as income, education, unemployment, cigarette and alcohol consumption, and population demographic characteristics are also included in the aggregate health production function to control for potential determinants of mortality that may be correlated with insurance coverage. The data on health insurance coverage by state come from the U.S. Census Bureau. We also collected data on a large number of additional variables from a variety of sources to construct a unique and rich dataset for use in this study.

More Bad News About High Gasoline Prices: A Look at Adult Cigarette Demand

Presenter:

John Tauras

Authors:

John Tauras, Sara Markowitz

Chair: Rosalie Pacula; Discussant: Don Kenkel Wed June 7, 2006 9:45-11:15 Room 309

This paper is about the spending choices of youth, with a particular focus on how the demand for cigarettes and alcohol are influenced by changes in the prices of other products. Youth tend to have small incomes and limited needs, with the result that many students spend the bulk of their income on only a few items. Fast food, clothing and entertainment make up the majority of products purchased by teenagers. The hypothesis to be tested in this project is that changes in the prices of the other goods commonly bought by teenagers and young adults will affect budget allocations and thereby affect the demand for alcohol and cigarettes.

Does the economy affect teenage substance use?

Presenter:

Jeremy Arkes

Authors:

Jeremy Arkes

Chair: Rosalie Pacula; Discussant: Gulcin Gumus Wed June 7, 2006 9:45-11:15 Room 309

This research examines how teenage drug and alcohol use responds to changes in the economy. In contrast to the recent literature confirming procyclical alcohol use among adults, this research concludes that a weaker economy leads to greater marijuana and hard-drug use among teenagers. The results for alcohol use suggest no relationship. The findings are based on logistic models with state and year fixed effects, using teenagers from the NLSY-1997. The evidence also indicates that teenagers are more likely to sell drugs in weaker economies. This suggests one mechanism for countercyclical drug use—that access to illicit drugs is easier when the economy is weaker. These results also suggest that the strengthening economy in the 1990s mitigated what would otherwise have been much larger increases in teenage drug use.

MJ use in late adolescence and its affect on delinquency and crime

Presenter:

Catherine MacLean

Authors:

J. Catherine MacClean, Michael T. French, Rosalie Liccardo Pacula

Chair: Rosalie Pacula; Discussant: Sara Markowitz Wed June 7, 2006 9:45-11:15 Room 309

Despite small declines in recent years, marijuana use remains high, particularly among adolescents for whom marijuana is the “drug of choice”. Unlike other illicit drugs, whether marijuana use generates crime remains fiercely debated as the criminogenic effects of marijuana have not been definitively determined. In this study, we use data from the National Epidemiologic Survey on Alcohol and Related Conditions to explore the effects of adolescent marijuana use on a range of delinquency and criminal activities. After controlling for the endogeneity of marijuana use in all specifications, we find strong evidence that various measures of marijuana consumption are related both to delinquency and criminal activity. These results have interesting policy and public health implications regarding marijuana use during adolescence.

Behavioral Economics and Conflicts of Interest

Presenter:

George Loewenstein

Authors:

George Loewenstein

Chair: Mark Schlesinger; Discussant: Mark Schlesinger Wed June 7, 2006 9:45-11:15 Room 325

Market Responses to Consumer Self Control problems

Presenter:

Botond Kosegi

Authors:

Botond Kosegi

Chair: Mark Schlesinger; Discussant: Mark Schlesinger Wed June 7, 2006 9:45-11:15 Room 325

Choice, Price Competition, and Complexity in Health Insurance Markets

Presenter:

Richard Frank

Authors:

Richard Frank

Chair: Mark Schlesinger; Discussant: Mark Schlesinger Wed June 7, 2006 9:45-11:15 Room 325

Methods for Comparing Health Disparities Over Time and Space

Presenter:

Tom McGuire

Authors:

Thomas G. McGuire, Ben Le Cook, Jeanne Miranda

Chair: Albert A. Okunade; Discussant: Christopher J. Ruhm Wed June 7, 2006 9:45-11:15 Room 326

Assessing Socio-economic Disparities in Household Health Expenditures for Pre- and Post- 1997 Economic Crisis in Thailand

Presenter:

Chutima Suraratdecha

Authors:

Chutima Suraratdecha, Albert A. Okunade

Chair: Albert A. Okunade; Discussant: Christopher J. Ruhm Wed June 7, 2006 9:45-11:15 Room 326

Disparity research on health care access, process, outcome, cost and expenditures are rich and substantial for the developed countries (Kirby, Taliaferro, and Zuvekas, 2006). Similar studies are sparse for most Asian countries, including Thailand, mainly due to the lack of good micro databases. Reliable national household survey data observed at biennial intervals recently became available for Thailand, however. Therefore, consistent with the falling purchasing power of the bhat currency, high costs of imported drugs and medical devices, and reduction of public and private health services emanating from the 1997 economic crisis, Thai households are hypothesized to differentially adjust health care spending across socioeconomic strata. The goals of this paper are to measure the impact of the sudden economic shift emanating from the economic crisis on pre- and post- crisis household health expenditures, and to provide insights into the relationship of variations in health care spending across income quintiles and disparities in economic, regional (or provincial), and demographic factors including proximity to death. The household data for this research are the 1994, 1996, 1998, and 2000 national Socio-economic Surveys (SES), covering 98,632 Thailand households and included detailed information on household income, expenditures and demographics. Findings from Tobit regression models of health expenditure indicate that the 1997 economic crisis negatively affected household health expenditure differentially across income quintiles. Moreover, health expenditures are significantly influenced by household median age and proximity to death. Some implications for policy and further studies are explored.

Health Insurance Disparities in Traditional and Contingent/Alternative Employment

Presenter:

Shelley White-Means

Authors:

Shelley I. White-Means, Joni Hersch

Chair: Albert A. Okunade; Discussant: TBA Wed June 7, 2006 9:45-11:15 Room 326

Relative to whites, Hispanics and blacks are less likely to have employer health insurance coverage. We examine whether ethnicity or race affects employment in traditional jobs or in contingent and alternative work arrangements, and whether ethnicity or race affects insurance offer, eligibility, and/or enrollment, conditional on employment sector. Health insurance disparities relative to whites are more pronounced for Hispanics, primarily due to disparities in employment by firms that offer coverage. Eliminating racial/ethnic disparities in offers, eligibility, and takeup would increase insurance coverage rates of Hispanics in traditional jobs and of both Hispanics and blacks in contingent and alternative jobs.

Testing for Statistical Discrimination: Lessons from NHANES III, 1988-1994

Presenter:

Danielle Rose Ash

Authors:

Danielle Rose Ash

Chair: Albert A. Okunade; Discussant: TBA Wed June 7, 2006 9:45-11:15 Room 326

The Effect of Health on Changing Labor Outcomes in Transition China

Presenter:

Will Dow

Authors:

Will Dow, Deokhee Yi

Chair: Paul Schultz; Discussant: John Mullahy Wed June 7, 2006 9:45-11:15 Room 332

Long Term Consequences of Family Planning and Reproductive Health Intervention in Matlab, Bangladesh

Presenter:

Paul Schultz

Authors:

Paul Schultz, Shareen Joshi

Chair: Paul Schultz; Discussant: John Mullahy Wed June 7, 2006 9:45-11:15 Room 332

Immediate and Longer-Term Effects of Health on Socio-economic Success

Presenter:

Duncan Thomas

Authors:

Duncan Thomas, Elizabeth Frankenberg, Jed Friedman, Jean-Pierre Habicht, Nick Ingwersen, Nathan Jones, Christopher McKelvey, Gretel Pelto, James P. Smith, Bondan Sikoki, Cecep Sumantri, Wayan Suriastini

Chair: Paul Schultz; Discussant: John Mullahy Wed June 7, 2006 9:45-11:15 Room 332

HIV Treatment Breakthroughs and Precaution Among the Uninfected

Presenter:

Darius Lakdawalla

Authors:

Darius Lakdawalla, Neeraj Sood

Chair: Arleen Leibowitz Wed June 7, 2006 9:45-11:15 Room 335

Distance and Time Costs of HIV Testing

Presenter:

Arleen Leibowitz

Authors:

Arleen Leibowitz, Stephanie Taylor

Chair: Arleen Leibowitz Wed June 7, 2006 9:45-11:15 Room 335

Estimating the Impact of Medical Innovation: A Case Study of HIV Antiretroviral Treatments

Presenter:

Mark Duggan

Authors:

Mark G. Duggan, William N. Evans

Chair: Arleen Leibowitz Wed June 7, 2006 9:45-11:15 Room 335

The Effects of Free-Standing Ambulatory Surgery Centers on Hospital Surgery Volume

Presenter:

John Bian

Authors:

John Bian, Michael Morrisey

Chair: Dean Lillard; Discussant: James Marton Wed June 7, 2006 8:00-9:30 Room 121

Rationale: Hospitals traditionally compete among themselves for health services such as surgical procedures. The growing number of free-standing ambulatory surgery centers (ASCs) poses a potential threat to hospital surgery services. However, there has been little empirical evidence on the effect of ASCs on hospital surgery volume.

Objective: This study examined the effect of the growth in ASCs on community hospital outpatient and inpatient surgery volume.

Methods: Using secondary data of the 1992-2001 American Hospital Association Annual Survey files, the 2002 Medicare Online Survey Certification and Reporting System, an HMO penetration file, and the Area Resource Files, we constructed a balanced Metropolitan Statistical Area (MSA) panel dataset including 317 MSAs from 1992-2001. The unit of analysis was a MSA-year. Ordinary least squares regressions with MSA and year fixed effects were used to control for MSA-level heterogeneity and time trends. Three dependent variables were the log-transformed hospital outpatient, inpatient, and total (inpatient and outpatient combined) surgery volumes. The key explanatory variable was the number of ASCs per 100,000 people. Other covariates included health maintenance organization (HMO) penetration, hospital concentration measured by the Herfindahl-Hirschman Index, supplies of surgeons and physicians, and demographic and economic characteristics. The standard errors were adjusted via Huber standard errors correction.

Results: The panel data included a total of 3170 MSA-years. From 1992-2001, average outpatient surgery volume at the MSA-level increased by 23% from 58,783 to 72,111, average inpatient surgery volume decreased by 12% from 50,778 to 44,911, and average total surgery volume only increased by 7% from 109,561 to 117,022. During the same period, the number of ASCs increased by 143% from .66 to 1.69 per 100,000 people, HMO penetration nearly doubled, and hospital markets became more concentrated. In regression analysis, the number of ASCs per 100,000 people was inversely associated with outpatient and total surgery volumes (p<.01) but was not associated with inpatient surgery volume (p>.10). Other thing equal, an increase in 1 ASC per 100,000 people is associated with a decrease of 4.1% in outpatient surgery volume and a decrease of 1.8% in total surgery volume. In addition, our study showed that increased hospital concentration raised hospital outpatient and total surgery volumes. But we found no associations of HMO penetration and hospital surgery volume.

Conclusions: This was the first study using nationally representative MSA-level panel data from 1992-2001 to show that ASCs may lead to a decline in hospital total surgery volume, largely driven by decreased hospital outpatient surgery volume. Additional research needs to focus on the impact of ASCs on hospital provision of charitable care and quality of care.

The Quality of Diabetes Care by Insurance Status in Community Health Centers

Presenter:

James Zhang

Authors:

James Zhang, Anne Kirchhoff, Jennifer Walk, Marshall Chin

Chair: Dean Lillard; Discussant: James Marton Wed June 7, 2006 8:00-9:30 Room 121

Rationale: Access to quality care is important to eliminate health disparities and increase the quality and years of healthy life for all persons in the United States. Community health centers (CHCs) provide critical primary health care to 12 million Americans with or without health insurance in medically underserved areas. Over forty percent of CHC patients are uninsured and over one-third are on Medicaid; therefore, understanding how insurance status relates to care at CHCs is important for improving medical care for vulnerable CHC patients.

Objective: The objective of this study is to compare the quality of care for diabetes patients by insurance status at 27 CHCs, including patients without health insurance and Medicaid/Medicare Dual Eligibles (DEs).

Methodology: We sampled 27 CHCs in 17 West Central and Midwest states in the year 2002. A total of 2,052 diabetes patients were enrolled in the study. We developed an algorithm to expand the insurance groupings commonly reported in the literature and categorized our diabetes patients into six mutually exclusive groups that included a Medicare/Medicaid dual eligible (DE) group, as well as groups for no insurance, Medicare without Medicaid, Medicaid without Medicare, private insurance, and other. We used a set of six quality of care indicators developed by National Committee for Quality Assurance (NCQA) to assess the quality of care. We applied multivariate regression analysis technique to analyze the association between the insurance coverage and quality of care, adjusting for age, gender, race, one dummy variable for urban location of services, seven dummy variables for medical comorbidity/complications, and CHC site fixed-effects. The quality of care in those CHCs were further compared to that in commercial managed care plans located in these states.

Results: This study reveals that in CHCs there are differences in quality of diabetes care by insurance status. Patients without insurance, and younger patients with Medicaid fared the worst in six comprehensive diabetes care quality indicators. In contrast, Medicaid/Medicare dual eligibles received better quality of care despite being more frail and vulnerable both medically and economically. Patients with private insurance did significantly better in four of the six quality indicators.

Conclusion: Our findings support the initiative to create and expand CHCs in communities to improve access to care for the poor and vulnerable, such as the Federal Health Center Growth Initiative supported by the current administration. Our study also argues for coupling expanding CHC service locations with increasing insurance coverage to achieve the best health outcomes for the hundreds of thousands indigent diabetes patients who rely on safety-net providers for their primary care.

What is the Value of a Critical Access Hospital?

Presenter:

Paul McNamara

Authors:

Paul McNamara

Chair: Dean Lillard; Discussant: James Marton Wed June 7, 2006 8:00-9:30 Room 121

The Critical Access Hospital (CAH) Program, which provides cost-based reimbursement to isolated small rural hospitals, as opposed to the prospective reimbursement formula used for most other hospitals, provides an example of how equity concerns are implemented in the context of US health policy. However, no economic analysis exists that measures the value of providing access to rural hospital services delivered in a specific location. This paper measures the value of locally provided rural health services in the specific example of the Critical Access Hospital (CAH) program. Understanding this value is necessary for the evaluation of current federal rural health policy.

This paper proposes the travel-cost hospital choice method as the means of developing an estimate for the location-specific benefits provided by a small rural hospital participating in the CAH program. The travel cost or time cost method of measuring the value of access to health services builds upon Acton’s seminal work (1975), and has been broadly applied in the analysis of health care demand, with a notable example being the work of Gertler and van der Gaag (1990). However, the method and its extension to the valuation of services has not been applied often to rural health services in higher income countries, with two exceptions being the work by Clarke (1998) and McNamara (1999).

As an illustration of the general approach and to obtain an estimate of the value of a CAH in Illinois, this paper presents an analysis of the locational demand for hospital services by patients with pneumonia using Illinois 2001 hospitalization data. Using a 40% random sample of the pneumonia cases in the first quarter of the year leads to 4618 hospitalization cases. The per trip estimates range from $14.93 to $17.41 in the case of a small CAH in Benton, Illinois to between $43.44 to $46.91 on average for all the pneumonia cases of rural Illinoisans examined. Assuming the generalizability of these CV estimates, we find that a rural hospital provides significant benefits to the community simply as a function of its location and the community’s relative distance to alternative sources of care. Average estimates of the value of a rural hospital in Illinois (assuming 1200 inpatient admissions) ranged from $17,916 for a rural hospital in Benton, Illinois to an average value of $56,292 annually based on the entire data set of 4816 pneumonia hospitalizations. These estimates of value are much smaller than net financial cost (to Medicare compared to the CAH’s previous Medicare revenues) of the CAH program’s cost-based reimbursement for participating hospitals, which anecdotally is costing between $250,000 to over $1,000,000 per participating hospital. It should be noted that these estimates do not include some other important sources of value associated with a rural hospital: outpatient visits are not considered; the value of life saved through the presence of a nearby emergency room is not considered; and, the option value that rural residents experience because of the presence of a hospital in their community or area is not considered.

Enrollment in Health Insurance Plans Fully Paid by Employers

Presenter:

Alice Zawacki

Authors:

Alice Zawacki, Amy Taylor

Chair: David Bradford; Discussant: David Bradford Wed June 7, 2006 8:00-9:30 Room 213

Rationale: In 2003, 44% of establishments in the U.S. offered at least one health insurance plan that required no contribution from the employee for single coverage. However, not all eligible employees enrolled in these plans. Some eligible employees might want family coverage, while only single coverage is fully paid, or perhaps these plans are unattractive.

Objective: The objective of this study is to examine health insurance enrollment in establishments that pay 100% for at least one plan and to study the plans that employees were enrolled in.

Methodology: We analyze data from the 1997-2003 MEPS-IC (Medical Expenditure Panel Survey - Insurance Component), which surveyed a nationally representative sample of establishments about health insurance plans offered to employees. Data includes premiums, contributions by employers and employees, and benefit characteristics. The MEPS-IC also provides information on employer characteristics (e.g., size, ownership, and industry) and workforce characteristics (e.g., percent female, unionization, and wages).

Bivariate analysis is used to look at the percent enrolled at both the establishment and plan level. We look at employers offering only one plan and more than one plan, further subsampled into those that paid 100% of the premium cost and those that did not.

To help explain why all eligible employees do not enroll in fully paid plans, we will compare enrollment in plans where single coverage is fully paid, but family coverage is not, and enrollment in plans with both single and family coverage fully paid. This will help identify whether eligible employees may not be enrolling in fully paid single coverage plans because they want family coverage.

To examine the impact of a plan’s attractiveness on enrollment in fully paid plans and those that are not, we compare their characteristics. We focus on attributes that might make a plan more attractive to some employees, such as provider choice, coverage for pre-existing conditions, and no gatekeeper. Multivariate analysis will also be done to explain the impact of multiple dimensions of attractiveness on enrollment and compare the plans paid 100% with those that are not. Here we will focus only on plans from establishments offering more than one plan, in order to control for workforce characteristics.

Results: In 2003, only 87% of eligible employees in establishments that offered only one plan, with fully paid single coverage, enrolled in the plan. At the same time, only 33% of eligible employees in establishments that offered more than one plan enrolled in plans that had fully paid single coverage. Plans that were paid 100 percent by employers generally had gatekeepers, did not cover pre-existing conditions or outpatient prescriptions, and had the highest out-of-pocket expense limits.

Conclusions: Preliminary results indicate that some eligible employees may not be enrolling in fully paid health plans because the plans are not attractive to them. Further analysis will be done to examine whether employees do not opt for plans with fully paid single coverage because they want family coverage.

The Impact of Increased Tax Subsidies on the Insurance Coverage of Self-Employed Families: Evidence from the 1996-2003 Medical Expenditure Panel Survey

Presenter:

Thomas Selden

Authors:

Jessica Vistnes, Thomas Selden

Chair: David Bradford; Discussant: David Bradford Wed June 7, 2006 8:00-9:30 Room 213

Over the past two decades, tax policy has provided increasing subsidies for health insurance purchased by self-employed persons. The share of premiums paid by the self employed that are excludable from federal income taxation rose from a minimal share before 1986 to 30 percent by 1996 and 100 percent as of 2003, with many states mirroring or exceeding the pace of federal change. This paper examines the impact of increased tax subsidies on the insurance coverage of self-employed workers and their families using the 1996-2003 Medical Expenditure Panel Survey. Following Gruber and Poterba (1994), the analysis examines the impact of self-employed workers’ declining tax prices, using as a control group employed workers, a group for whom tax prices held relatively constant. The analysis yields an elasticity of private coverage for adults in self-employed families that exceeds -1 in magnitude when estimated using the most widespread measure of tax price. This elasticity estimate exceeds most estimates in the literature on employed workers. Using a more comprehensive measure of the relative price of insurance, the elasticity estimate for adults in self-employed families is even larger. These results suggest that self-employed workers do respond to tax subsidies by increasing private coverage. Increased tax subsidization of self employment coverage also appears to have reduced reliance on public coverage, although the magnitude of this “reverse crowd out” is small. Tax subsidies are found to have the expected effect on the coverage of children in self-employed families, although the impact on children’s coverage is only about half of that found for adults.

The Effect of Mandatory Employer-Sponsored Health Insurance on the Use of Part-Time versus Full-Time Workers: The Case of Hawaii.

Presenter:

Gerard Russo

Authors:

Sang-Hyop Lee, Gerard Russo, Lawrence Nitz, Abdul Jabbar, Rui Wang, Thamana Lekprichakul

Chair: David Bradford; Discussant: David Bradford Wed June 7, 2006 8:00-9:30 Room 213

Authors: Sang-Hyop Lee (leesang@hawaii.edu), Gerard Russo (russo@hawaii.edu), Lawrence H. Nitz (lnitz@hawaii.edu), Abdul Jabbar (jabbar@hawaii.edu), Rui Wang (ruiw@hawaii.edu) and Thamana Lekprichakul (thamana@hawaii.edu), University of Hawaii.

Title: The Effect of Mandatory Employer-Sponsored Health Insurance on the Use of Part-Time versus Full-Time Workers: The Case of Hawaii.

Overview: The Hawaii Prepaid Health Care Act (PHCA) of 1974 is a unique law which requires private-sector firms to provide health insurance to their employees working at least 20 hours per week. It represents a natural experiment which is ideally suited for an investigation of the impact of mandatory ESI on labor force utilization with particular emphasis on part-time and full-time workers.

Hypotheses: The Hawaii 20-hour rule is thought to have two possible effects on the distribution of the workforce by hours worked. First, firms may seek to employ more part-time workers a legal avoidance of the mandated labor expense associated with ESI. Alternatively, we hypothesize an effect in the opposite direction. This arises from the recognition that mandated ESI represents a fixed-cost per employee per month. The lump-sum nature of health insurance premiums implies the incremental cost of utilizing a full-time worker more intensely is absent any additional ESI expense. This second hypothesis states that mandatory ESI will shift the distribution of equilibrium employment by hours worked towards full-time workers, implying total labor utilization will rise but total employment will fall. We conduct an empirical investigation of these hypotheses.

Data & Method: We produce direct and model-based estimates of the distribution of employees by hours-worked, using 12-years of the Current Population Survey (CPS), Basic Monthly Survey and Annual Social and Economic (ASEC) Supplement 1994-2005. These are estimates of employment patterns for working age adults for Hawaii, the U.S. as a whole and several comparative States including Nevada, Michigan, California and Florida controlling for worker characteristics and industrial structure. We treat the Hawaii distribution as the factual and the U.S., Michigan, Nevada, California and Florida distributions as the counter-factual.

Results: We find utilization of employees working between 20 and 35 hours per week, is reduced under Hawaii’s employer mandate. We also find that mandated ESI increases the proportion of part-time workers (i.e., less than 20-hours per week) and also increases the utilization of labor from full-time workers above 36-hours per week. Generally, the shifts in the distribution of labor force are modest but statistically significant.

Conclusion: Mandating ESI will increase the cost of labor for many firms who would not otherwise provide coverage and reduce cash wages as a proportion of total compensation. The equilibrium response is two-fold. First, more part-time employment will result as employers and employees legally avoid the mandate. Second, employers will utilize full time workers more intensely by increasing hours, thereby shifting the upper distribution of employees by hours worked further to the right. On net, the distribution of employment by hours worked will be “hollowed out” in the 20-35 hour range as these employees are the relatively most expensive to employ under a Hawaii 20-hour mandate.

Does College Education Impact Obesity and Smoking? Evidence From the Pre-Lottery Vietnam Draft

Presenter:

Bo MacInnis

Authors:

Bo MacInnis

Chair: James Burgess; Discussant: James Burgess Wed June 7, 2006 8:00-9:30 Room 225

The drastic change in drafting rules from the pre-lottery Vietnam draft to the draft lottery creates a discontinuity in postsecondary educational attainment between males of cohorts 1946-1950 and their immediately adjacent cohorts. Unlike cohorts 1942-1944, males of cohorts 1946-1950, who were appropriately aged for both the draft and college, could easily obtain draft deferments by enrolling in college during the high-induction pre-lottery period. For males of cohorts 1951-1953, enrolling in college would no longer exempt them from the draft because of the elimination of college deferments by the draft lottery. Consequently, males’ college education rate rose noticeably for cohorts 1946-1950 and then fell abruptly for cohorts 1951-1953. We exploit this exogenous discontinuity gap in college education to infer a causal effect of education on health.

Using the National Health Interview Survey 1998-2003, we find the pre-lottery Vietnam draft caused approximately a 4-5% increase in college enrollment and 3-4% increase in college completion. We find strong evidence that college completion reduces the probability of obesity and increases the probability of smoking cessation. There is moderate evidence that college completion also reduces the probability of smoking initiation and Type 2 diabetes. The evidence of the impact of college enrollment or associate degree attainment on these health outcomes is moderate to weak.

The economic benefit of college completion, in terms of the reduced probability of smoking and obesity and consequent reduced medical expenditures and productivity losses that are attributable to smoking and obesity, amounts to more than $150,000 lifetime savings total per college graduate, with the lower bound of more than $75,000. The lower bound savings are more than three times the per-student amount of public financing of college education i.e. $22,234, and represent nearly 15% of the lifetime return to a college degree compared to a high school diploma in monetary earnings i.e. $500,000.

The Effect of Education and Parental Education on Obesity

Presenter:

Mark Stehr

Authors:

Mark Stehr

Chair: James Burgess; Discussant: James Burgess Wed June 7, 2006 8:00-9:30 Room 225

Economists have expended a great deal of effort to determine the effect of education on wages and productivity. Recent research has broadened the scope of this investigation to include the non-pecuniary benefits that education may provide such as improvements in health. Lleras Muney (2002) finds that high school education decreases mortality, but is silent on the exact mechanisms through which education operates. DeWalque (2003) shows that college education has a causal role in lowering smoking rates, but more research is needed to understand the other channels through which education exerts its positive influence on health. At the same time, economists are actively investigating the relationship between markers of socioeconomic status, such as income and education, and child health (see Currie and Stabile, 2003).

This paper tests the hypothesis that more schooling at the college level leads to (a) lower levels of obesity and (b) lower levels of obesity among one’s children. Obesity is a particularly important health outcome because it is rapidly approaching smoking as a cause of premature morbidity and mortality. This hypothesis cannot be tested by examining a simple association between education and body mass index (BMI) because both of these outcomes may be influenced by unobservable characteristics of the individual. For example, the relative value individuals place on current and future consumption may vary. Those who place a high value on future consumption may make large investments in education and health while they are young that involve sacrifices in the form of foregone wages and leisure time. Those who place a high value on current consumption may not be willing to make these sacrifices when they are young, and as a consequence may enjoy lower earnings and health when they are older. Thus, to infer from the simple association between education and BMI that education reduces obesity risk is invalid.

Ideally, to isolate the effect of education on obesity, one would randomly assign individuals to different education levels and then follow the evolution of their BMI over time. Because this is clearly infeasible, I instead use a quasi-experimental design that attempts to mimic this random assignment. Use of this quasi-experiment requires that the experiment predict education, but have no direct effect on BMI. My quasi-experiment is the number of colleges and universities in an individual’s county of residence at age 17. Previous researchers have relied on this quasi-experiment to study the effect of education on wages (Card, 1995) and civic participation (Dee, 2004). To acquire data on schools, I use the Higher Education General Information Survey (HEGIS), which provides data on the number of 2-year and 4-year colleges in each county in the United States. Then, I match this measure of college availability by county with respondents from the NLSY79 and their children from the NLSY79 Child/Young Adult Survey. Preliminary OLS results indicate a strong negative association between education and obesity, but it is too early to report results from the quasi-experimental research design outlined above.

How Does Parental Education Affect Child Health?

Presenter:

Kosali Simon

Authors:

Kosali Simon, Dean Lillard, Maki Ueyama

Chair: James Burgess; Discussant: James Burgess Wed June 7, 2006 8:00-9:30 Room 225

Estimating the causal effect of education on one’s own or one’s children’s health is complicated by the fact that unobserved variation across individuals could cause both health and education. Little prior research considers the effect of parent’s education on child health in a developed country context. A recent exception is Currie and Moretti (QJE, 2003) who show that exogenous increases in college education induced by college openings has a beneficial impact on an infant’s health. No study has examined how parental high school completion causally affects infant, child or adolescent health in the US. Our paper provides answers to this question, and investigates mechanisms that may be responsible for this effect. We exploit variation in state educational testing policies (graduation requirements and GED) that lead to exogenous differences in high school educational attainment. We conduct our study with two data sets; the National Longitudinal Survey of Youth, 1979 (NLSY79) cohort, and the Natality Detail Dat??????f health care services, or through health related behaviors.

Intergenerational Obesity Transmission and Correlations of Human Capital Accumulation

Presenter:

Timothy Classen

Authors:

Timothy Classen

Chair: Vilma Carande-Kulis; Discussant: TBA Wed June 7, 2006 8:00-9:30 Room 226

The goal of this research is to provide an estimate of the intergenerational persistence of obesity and its influence on human capital accumulation. I measure the intergenerational correlation of weight status between women and their children when both are at similar stages of development. This study contributes to the literature on the role of health as a mechanism in the correlation of economic status between generations. Prior studies of obesity have found a strong relationship between weight status and economic outcomes. Thus, the transmission of obesity between generations may explain a portion of the intergenerational correlations of economic status that have previously been characterized. Using the National Longitudinal Survey of Youth 1979 (NLSY79) and the Children and Young Adults of the NLSY79, I compute the Body Mass Index (BMI) of women and their children when both generations are between the ages of 16 and 24. In the sample used, the measured intergenerational correlation of BMI is roughly 0.35. This result differs by the gender of the offspring with a BMI correlation between female children and their mothers of 0.38, compared to a significantly lower BMI correlation of 0.32 between mothers and their sons. Intragenerational correlations are slightly lower and are highest for same-gender siblings. Women who were overweight in early adulthood are found to have a lower likelihood of high school completion and produce offspring who are also less likely to complete high school.

Food Insecurity, Food Storage, and Obesity

Presenter:

Sean Cash

Authors:

Sean Cash, David Zilberman

Chair: Vilma Carande-Kulis; Discussant: TBA Wed June 7, 2006 8:00-9:30 Room 226

Although individuals with poor food security might be expected to have reduced food intake, and therefore a lower likelihood of being overweight, some empirical evidence has indicated that overweight status is actually more prevalent among the food insecure (Townsend et al., 2001; Adams et al., 2003; Sarlio-Lähteenkorva and Lahelma, 2001; Alaimo et al., 2001). As obesity is associated with excessive energy intake, and hunger reflects an inadequate food supply, such observations would appear to be paradoxical (Dietz, 1995). We develop an economic model that shows that this apparently paradoxical result is consistent with rational behavior regarding food availability risk and the effectiveness of food storage options.

We construct a two-period model of utility maximization, in which periods may differ by the availability of food for harvest. The availability of food in the current period is deterministic, whereas the availability of food in the second period is stochastic. Utility in each period is determined by the contemporaneous consumption of food, health status, and time allocated to leisure. Health status is determined, in part, by the stock of internally stored energy. Individuals can either consume food, store food physically (externally) for a future period, or store energy internally (i.e., as body fat). Both forms of storage are subject to depreciation. Individuals seek to maximize utility by allocating time and first period consumption decisions, subject to both time and food availability constraints.

The model suggests that if physical storage is ineffective and the health effect in the second period dominates the consumption effect, then there will be extra consumption in the first period for storage of energy as body fat. The amount of internal storage increases as the variance of food productivity in the second period increases, which is consistent with the empirical observation of a positive relationship between food insecurity and the incidence of overweight. The model further indicates that higher climatic energy needs (e.g., colder climates) and lower efficiency of external food storage will also contribute to increased accumulation of body fat.

The theoretical model is then adapted for use in two simulations. The first simulation indicates that the model also predicts a higher probability of survival of individuals adapting an internal energy storage strategy in the face of increased food insecurity. This suggests that the model applies not just under an assumption of reasoned utility maximization, but also to explanations involving evolutionary behavior. In the second exercise, we adapt the model for use in an empirical simulation involving data from the U.S. Continuing Study of Food Intake in Individuals, showing that the model is consistent with previously noted results regarding the incidence of food insecurity and overweight in those data.

Can you afford to exercise? Effects of time and money income on physical activity and the body mass

Presenter:

Nidhi Thakur

Authors:

Nidhi Thakur

Chair: Vilma Carande-Kulis; Discussant: Timothy Classen Wed June 7, 2006 8:00-9:30 Room 226

Rationale: Much has been told about how technological advancements have lowered the price of food and reduced physical demands of work, both of which have been attributed to increased body mass amongst Americans. However, while this explanation of obesity does explain long-term trends in body mass, it should not be forgotten that basically obesity is a micro-level phenomenon. At any point in time individuals take technological advancements as given and then they make behavioral choices which show up in heterogeneity in the weight outcomes. These individual choices are a function of various socio-economic processes which may interact in various ways.

Objectives: The objective of this paper is to analyse the determinants of physical exercise and its impact on body mass.

Methodology: We estimate a system of simultaneous equations where weight is determined by exercise levels besides various socio-economic factors and exercise level is in turn determined by weight and various socio-economic factors. We believe that exercise by its sheer time intensiveness has a large time cost, even when its direct monetary costs may be low, for example in a simple exercise of walking in the park. The time costs therefore add to the opportunity costs of undertaking physical exercise. To the extent that individuals are uniformly endowed with 24 hours in a day, clearly they will allocate their time such as to maximize their utility a crucial component of which is the money or budget constraints. Thus allocation of time to physically demanding activities will determine the body weight of an individual. However, the need to do exercise may itself be motivated by the body weight. We use the NLSY79 data for the years 1998-2002, the only years for which the NLSY explicitly asked questions on physical activity level. To our knowledge there is no other paper which has used this aspect of NLSY till now.

Results: Preliminary analysis suggests that lack of physical exercise can explain part of an increase in body-weight of an individual. Additionally we find that physical exercise, is most lacking in some income groups.

Conclusions: To the extent that individuals do not choose the technology levels in the economy, their choices are revealed through their use of their resources such as to maximize utility. Since overweight does have a disutility clearly individuals who still end up with an uncomfortable level of body weight must be constrained either by money income, or low discount rates, or time. We approached the problem of obesity from time perspective, and our analysis suggests that policy should intervene in the time use of individuals such as to gear them towards some regular basic level of physical exercise.

Storm Clouds on the Horizon - Expected Adverse Selection in Medicare Prescription Drug Plans

Presenter:

Steven Pizer

Authors:

Steven Pizer, Austin Frakt, Roger Feldman

Chair: Carole Gresenz; Discussant: Bill Encinosa Wed June 7, 2006 8:00-9:30 Room 235

Objective: To estimate the costs and benefits from a Neonatal Intensive Care Unit (NICU) case management program. Background: Starting in 2005 ParadigmHealth (PH) began administering its NICU case management program for Blue Shield of California (BSC) members. During the 2 years prior there was no NICU case management program in place. This program assigns a NICU-trained RN case manager to each enrolled patient. The on-site RN case manager consults with ParadigmHealth’s neonatologists. The PH team works with the hospital’s neonatology staff to develop a treatment plan using evidence-based guidelines. In addition PH provides patient education and creates a post-discharge plan with the family. PH receives a regular data feed from the BSC inpatient authorization system. Patients are enrolled 2-3 days after admission to the NICU. This program is expected to reduce the initial length of stay as well as reduce readmissions. Methodology: This program was implemented system-wide in January 2005, with no control group. However BSC NICU data was available during a two-year period prior to program implementation (2003-2004). To control for possible differences in case-mix across time we stratified the cases into 21 groups. There were seven birth weight categories and three clinical groups (surgical, congenital abnormalities or respiratory distress, and other complications). 2015 NICU cases were included in the baseline analysis. Cases that were discharged within 3 days of admission and cases with missing or conflicting birth weight observations were excluded. There are also several clinical exclusions from the program. These conditions (such as transplant surgery and extracorporeal membrane oxygenation) are all rare within the BSC population. Average length of stay (ALOS) was calculated for each of the 21 weight/clinical groups. This length of stay included any readmissions or transfers. The analysis was repeated with data from 2005. We then calculated the difference in weighted ALOS between the 2003-2004 baseline and the 2005 treatment groups. Preliminary Results: The ALOS for the 2003-2004 baseline group was 24.3 days (N=2015). In the treatment group, 194 patients from 2005 1st quarter have complete follow-up. We found a reduction in ALOS of 3.5 days. These preliminary results are statistically significant with a p-value of 0.03. The program costs (vendor costs plus internal BSC costs) are substantially less then the cost savings from the reduction in NICU days. Readmission rates will be assessed when 2005 2nd quarter data is released. Limitations: Expensive NICU cases take longer to process then most hospital claims, with some cases not getting full adjudication for more the 180 days. Thus there may be further revisions to 2005 first quarter data. Data from the subsequent quarters will be available in late 2005 and early 2006.

Potential for adverse selection for the new Medicare drug benefit

Presenter:

Patrick Bernet

Authors:

Patrick Bernet

Chair: Carole Gresenz; Discussant: Steve Zuckerman Wed June 7, 2006 8:00-9:30 Room 235

Rationale: Enrollment in the new drug benefit program is voluntary for most Medicare beneficiaries. Such voluntary enrollment is often associated with concern over adverse selection.

Objectives: This paper first explores the potential for adverse selection through an assessment of the likely proportion for which enrollment in the new Medicare drug plan will be mandatory. This is followed with a study of the insuring habits of older people who already use prescription drugs regularly.

Methodology: Medicare beneficiary data is employed to estimate the proportion of recipients for whom enrollment in the new drug plan is voluntary. This represents the size of the population for which adverse selection is a valid concern. Data from the Health and Retirement Survey (HRS) is then used to analyze the insurance purchasing habits of people who take prescription drugs regularly. While HRS does not have information on the new drug insurance product, it does have information on the other insurance decisions, including the level of Medicare supplemental insurance, life insurance and long-term care insurance. An analysis relates the propensity to insure with prescription drug use. This study draws on theories relating individual risk preference to medical history.

Results: Medicare recipients who use prescription drugs regularly are more likely to purchase higher levels of Medicare supplemental insurance and are more likely to own long-term care insurance policies.

Conclusions: The higher propensity of routine prescription drug users to insure in other areas is likely to carry forward under the new Medicare drug benefit. As such, voluntary Medicare drug plan enrollment will likely be skewed towards those who use more prescription drugs than average, bringing fears of adverse selection to fruition. As with other forms of health insurance, success for insures may be primarily a function of avoiding adverse selection.

Income-Related Disparities in Kidney Transplant Graft Failures Are Eliminated by Medicare's Immunosuppression Coverage

Presenter:

Robert Woodward

Authors:

Robert Woodward, Ricardo Soares

Chair: Carole Gresenz; Discussant: Will Dow Wed June 7, 2006 8:00-9:30 Room 235

RATIONALE: The maintenance immunosuppressive (IS) regimens required following kidney transplantation cost approximately $1,000 per month, a financial burden that is especially difficult for lower income transplant recipients. The changing durations of Medicare’s coverage of IS medications for kidney transplant recipients have provided opportunities to estimate the impact of that coverage on income-related disparities in the survival of the kidney graft. Previously published analyses of Medicare’s 1994 extension from 1 to 3 years IS coverage demonstrated that the extra two years eliminated a previously significant income-related disparity in the 2nd and 3rd years post-transplant. In 2000, Medicare extend the IS coverage to the life of the graft for the elderly and disabled.

OBJECTIVE: This study seeks to estimate the proportion of the annual graft losses in the fourth and fifth year post-transplant that may be correlated with the loss of Medicare’s Immunosuppression coverage at the end of three years post-transplant.

METHODOLOGY: The most recent USRDS data allow up to a five year follow-up for patients transplanted between January of 1997 and December of 1999. Among this cohort, income-related differences in graft survival among individuals eligible for only three years of IS coverage were compared with income-related difference among individuals eligible for life-time IS coverage. Of the 13,491first kidney transplanted from cadaveric donors whose transplant was primarily financed by Medicare, 3,943 had grafts that survived uncensored for 3 years and 90 days or more and who used Medicare’s IS coverage for 3 years. Median income of the ZIP code of the patient’s residence from the 2000 Census was used as a proxy patient income. Kaplan-Meier plots and multivariate Cox Proportional Hazard models were used to identify significant differences income-related disparities between the graft survival of patients who then did use and did not use Medicare’s IS coverage in the first 3 months of the 4th year.

RESULTS: Kaplan-Meier model estimates indicated that: i) loss of Medicare’s Insurance Coverage increased graft failures by 56.3% (P<0.01) among low income individuals with incomes too high for Medicaid, and ii) 12.3% of all graft failures in years 4 and 5 after transplant may be attributed to the loss of Medicare’s insurance coverage.

CONCLUSION: Medicare’s extensions of IS coverage have consistently eliminated the previously existing income-related disparities in kidney graft survival. Unfortunately, individuals who received a transplanted kidney primarily financed by Medicare, who are not disabled, and who were under 62 at transplantation remain eligible for only 3 years of Medicare’s IS coverage.

Cost-effectiveness of implementation research: the VA QUERI program

Presenter:

Mark Smith

Authors:

Mark Smith, Paul Barnett, Andrea Shane

Chair: David Meltzer; Discussant: David Meltzer Wed June 7, 2006 8:00-9:30 Room 309

Objectives: (1) to assess how traditional cost-effectiveness analysis (CEA) methods must be tailored and expanded for implementation research; (2) to introduce QUERI, the national VA program to support implementation of medical best practices.

Methods: We will describe traditional CEA methods and their use in current VA research. Next we will discuss how implementation research differs from traditional clinical trials, and how this impacts both the range and measurement of economic outcomes. We will present data on economic studies within the QUERI program and suggest ways in which future projects could be used to test new methods.

Results: Implementing an intervention raises economic issues beyond those encountered in standard CEA. Data are needed on the costs and impacts of both the underlying intervention and the program that implements it. The societal perspective of a standard CEA may be less influential than a managerial perspective that emphasizes a short time horizon, fixed staffing and facilities, and community standards of care. The comparator intervention (“usual care”) may depend on the level at which the intervention takes place, which in turn affects the range of study designs available.

We have two major lessons: (1) An implementation effort itself has costs and effectiveness separate from the intervention it is spreading. This has two implications. First, cost-effective interventions may not be cost-effective when implemented. Second, the best response to poor cost-effectiveness during implementation may be to redesign the implementation strategy rather than to alter or drop the underlying intervention. (2) Economic analyses of implementation research should reflect the needs of end users at a variety of levels. Policymakers at local, regional, and national levels are likely to view cost burdens differently and may have differing thresholds for cost-effectiveness.

VA presents many advantages for studying implementation methods. These include a uniform electronic patient record system nationwide, a comprehensive set of encounter-level data open to researchers, the ability to link VA and Medicare records, and administrative information on the 140+ local VA health systems and the regional networks they belong to. Although they belong to a single national system, there is still considerable diversity in medical practice and administration among VA facilities. Nationally, VA has committed to implementing best practices throughout its system and considers economic analysis an important element of the process.

Conclusions: Improved economic analyses can and should be implemented alongside implementation projects. Doing so is feasible in terms of both data collection and cost. Researchers should consider VA a laboratory for developing and testing new CEA methods alongside implementation projects.

The Use of Time-Variant Attributes in Conjoint Analysis

Presenter:

Eric Nauenberg

Authors:

Eric Nauenberg, Richard Ito, Lusine Abrahamyan, Amir Azarpazhooh, Nancy Valencia Rojas

Chair: David Meltzer; Discussant: Scott Grosse Wed June 7, 2006 8:00-9:30 Room 309

Rationale: Conjoint analysis is a valuable tool in eliciting preferences for various treatment options and has helped to set priorities. The basic structure of such analyses involves making comparisons of alternatives against a status quo. The latter is one in which the values of attributes remain fixed while the attribute values for alternative treatments are varied to determine how preferences between options are affected. The requirement that the status quo be represented by a fixed set of attributes presents a problem in analyzing attributes that vary with time-so-called time-variant attributes or attributes that reflect first differences (e.g., X= X(t) - X(t+1)). By their nature, the baseline values (X(t)) of these attributes often vary alongside varying values for the first differences. With such attributes, the values associated with the status quo will also vary as the baseline values shift even though the first difference will always be zero reflecting no change. It appears, therefore, that such attributes can not be included in conjoint analyses.

Objective: This paper presents a method for coding time-variant attributes in conjoint analyses.

Methodology: This paper presents two treatment options-status quo and alternative—each with three attributes: 1. cost-effectiveness (CE), 2. budget impact (BI) in terms of dollars expended per HMO member per month (PMPM) and 3. change in newly budgeted dollars left unexpended after inclusion of alternative treatment in the formulary. The third attribute is a time-variant attribute. The following presents attribute levels for the two treatments.

Cost-Effectiveness, 3 levels (per QALY): 1. $50,000 vs. $50,000, 2. $50,000 vs. $100,000, 3. $50,000 vs. $180,000

Budget Impact, 2 levels (PMPM): 1. $0 vs. $200, 2. $0 vs. $400

Unexpended budget, 3 levels: 1. 5% (no change) vs. 5% to 4%, 2. 1% (no change) vs. 1% to 0%, 3. 1% (no change) vs. 1% to 0.5% over budget

Each of the time-invariant attributes could be coded as the value included in the above table. Regarding the time-variant attribute, the economist could use a set of dummy variables to represent the different levels and use “no change” as the reference group. Thus, “5% to 4%” could be represented by a dummy variable D1 and “1% to 0%”could be represented by a dummy variable D2 and “1% to 0.5%” over budget could be represented by a dummy variable D3. All three levels of this attribute for the status quo could be coded as “no change” or coded as a value of 0 for all three dummy variables. The value of the associated regression coefficients would capture the value that decision-makers place on both the magnitude of the change as well as differences at baseline.

Results: Probit regression is used to analyze the change in benefit (delta B) from adopting the alternative treatment.

Delta B = Beta1(CE) + Beta2( (BI) + Beta3( (D1) + Beta4( (D2) + Beta5( (D3)

The results of a November 2005 pilot analyzing preferences for alternative treatments for end-stage-kidney-disease will be presented (n=32).

Conclusion: This paper expands the scope of conjoint analysis by employing time-variant attributes.

Validity and Reliability of Willingness-to-Pay Estimates: Evidence from Two Overlapping Discrete-Choice Experiments

Presenter:

Peter Zweifel

Authors:

Peter Zweifel, Harry Telser, Karolin Becker

Chair: David Meltzer; Discussant: William Cartwright Wed June 7, 2006 8:00-9:30 Room 309

Discrete-choice experiments, while becoming increasingly popular, have rarely been tested for validity and reliability. This contribution purports to provide some evidence of a rather uniqe type. Two surveys designed to measure willingess-to-accept (WTA) for reform options in Swiss health care and health insurance are used to provide independent information w th regard to two elements of reform. The issue to be addressed is whether WTA values converge although the three overlapping attributes (a more restrictive drug benefit, delayed access to medical innovation, and a change in the monthly insurance premium) are imbedded in widely differing choice sets. Experimentt A contains rather radical health system reform options. while experiment B concentrates on more familiar elements such as copayments and the benefit catalogue. EWile mean WTA values differ between experiments, the tend to vary in similar ways, suggesting at least theoretical validity and reliability.

Information Technology Adoption and the Quality of Care in U.S. Hospitals

Presenter:

Timothy Simcoe

Authors:

Tim Simcoe, Dov Rothman

Chair: Stephen T. Parente; Discussant: Jonathan Ketcham Wed June 7, 2006 8:00-9:30 Room 313

There has been increasing interest over the past decade in using information technology (IT) to improve the quality of medical care provided by U.S. hospitals. For example, the Institutes of Medicine (IOM) frequently highlights the potential role of IT in a series of reports on quality improvement. Evidence for these claims frequently comes from event studies that focus on a particular technology and a narrow range of outcomes—such as prescription error rates following the adoption of Computerized Physician Order Entry (CPOE) systems. However, there is a broader literature on IT and productivity that generally finds substantial variation in the establishment-level benefits of IT adoption. This literature attributes variation in the productivity impact of IT to the presence of complementary business processes and organizational characteristics. This paper will examine the relationship between IT adoption and the quality of care at U.S. hospitals, with a focus on identifying complementarities between IT and particular business processes or local market characteristics. We plan to address the following questions: Do hospitals that adopt IT earlier or use it more intensively provide better quality care? If they do, which dimensions of quality are most influence by IT? Are there complementarities between different kinds of IT or between IT and other clinical technologies? And finally, are there complementarities between IT and other business practices or market characteristics? The primary methodological challenge for this line of research is the potential endogeneity of IT adoption. In particular, we might expect the hospitals adopting a particular technology to be precisely those facilities that will benefit most from it. To address this issue, we consider several approaches for isolating the causal impact of IT on the quality of care. One approach exploits small differences in the timing of adoption, by comparing quality outcomes at hospitals that have implemented IT to those who have contracted for the same technology but not yet implemented it. Another approach uses a statistical method called Inverse Probability of Treatment Weighted (IPTW) estimation, which generalizes propensity-score matching techniques that control for selection on observables to the case of time-varying treatments (i.e. adoption decisions).1 The data for this study come from several sources. Measures of hospital IT adoption come from The Dorenfest Complete IHDS+ Databases 1998-2002. This data contains demographic and information systems data for acute care facilities with 100 beds or more. We also plan to construct clinical technology adoption data using publicly available administrative discharge data from Florida (HCUP) and California (OSHPD). Finally, we measure quality using the Healthcare Cost and Utilization Project (HCUP) quality indicator set, and the Patient Safety Indicator Modules (PSI) available from the Agency for Healthcare Research and Quality (AHRQ).2…

Network Effects and Diffusion of Health Information Technology

Presenter:

Michael Furukawa

Authors:

Michael F. Furukawa

Chair: Stephen T. Parente; Discussant: TBA Wed June 7, 2006 8:00-9:30 Room 313

Health information technology (HIT) is widely-regarded as a key strategic resource to increase efficiency and improve quality of care. Despite growing interest in HIT by managers and policymakers, few studies have examined the determinants of HIT adoption. In particular, little is known about the role of network effects in the diffusion of HIT across hospitals and affiliated organizations. This study seeks to address this gap in the literature by examining the effect of system membership on the adoption of HIT by hospitals, sub-acute, and ambulatory facilities. The primary data source is the 2004 HIMSS Analytics (HA) database, which contains detailed information on the adoption of HIT by 1,453 integrated health delivery systems. The sample includes 3,989 hospitals, 3,007 sub-acute, and 18,008 ambulatory care facilities. For hospitals and sub-acute facilities, the HIT variables are classified into 4 categories: financials and business office; medical records and administrative; management and human resources; and clinical and ancillary departments. Variables are also created for specific HIT, particularly advanced clinical applications such as computerized patient records and computerized physician order entry. The HA database is linked to two supplemental data sets: 1) 2002 AHA Annual Survey of Hospitals, which provides information on hospital (staffed beds, ownership type, teaching status, etc.) and system characteristics (centralization, physician arrangement, insurance product, etc.), and 2) 2004 Area Resource File, which provides information on area characteristics (rural, per capita income, etc.). I estimate multivariate regression models to test the effect of system characteristics on HIT adoption, controlling for facility and area characteristics. The first model uses logistic regression to estimate the factors correlated with the likelihood of adoption of specific HIT applications. The second model uses negative binomial regression to estimate the factors associated with the level of HIT adoption, as proxied by the count of applications adopted within each HIT category. Finally, I test the robustness of the results to the potential endogeneity of system membership using appropriate econometric methods. Preliminary results suggest that network effects are a strong determinant of HIT adoption. In particular, facilities in systems that are more centralized and offering an insurance product are much more likely to adopt advanced clinical IT as well as have a higher level of HIT adoption. The consolidation and integration of hospitals, physicians, and affiliated organizations into integrated health delivery systems has important implications for the adoption and diffusion of HIT. System membership may confer “network effects” because HIT adoption confers benefits to the adopter as well as other affiliated facilities. The study finds evidence that system governance and integration play a key role in HIT adoption. This implies that HIT adoption decisions are made at the system-level and that organizational structure plays a key role in the diffusion of HIT across facilities within a system.

The financial and clinical value of hospital information technology: A study of complementarity between monitoring technologies and health system organization

Presenter:

Jeffrey McCullough

Authors:

Jeffrey S. McCullough

Chair: Stephen T. Parente; Discussant: Yunwei Gai Wed June 7, 2006 8:00-9:30 Room 313

Health information technology (IT) holds the promise of improved clinical outcomes at lower costs. The benefits of health information technology, however, may not be fully realized through the simple adoption of new technologies. Rather, health systems may need to simultaneously reorganize their operations to complement information technology. This study estimates the clinical and financial value of both monitoring technologies and integration as well as complementarities between these inputs; furthermore, this study allows for both adoption and integration decisions to be endogenously determined… Monitoring technologies present a particularly interesting case for understanding the relationship between technology and firm boundaries. Monitoring technologies might allow for more complete contracts, thus being complementary to less integration between physicians and hospitals—a decrease in firm boundaries. Conversely, monitoring might improve the efficiency of hierarchical management structures thus being complementary to greater physician-hospital integration—an increase in the boundaries of the firm. By estimating the complementarity between monitoring IT and integration, I test these competing hypotheses. This study utilizes data from the Dorenfest IHDS+ and 3000+ databases for the years 1994 through 2003. Together, these databases provide a nearly complete census of U.S. nongovernmental, acute-care hospitals with more than 100 beds for the years 1994 through 2003. These data provide detailed descriptions of the nature and timing of hospitals’ adoption of monitoring information system. Furthermore, the Dorenfest data have been combined with five additional sources of hospital and physician data for the years 1994 through 2003; specifically, American Hospital Association’s (AHA) database of hospital characteristics, the Medicare Cost Reports which provide hospital cost and case-mix-adjustment data, the HCUP data which provide further detail of hospital output and clinical outcomes, the Area Resource File, and Interstudy’s HMO and managed care data. Additional data regarding the hedonic price of hardware and technology worker wages have been obtained from the Bureau of Labor Statistics. This study will estimate models of hospital costs and quality as a function of technology adoption and organizational design. A system of simultaneous equations for hospital performance, vertical integration, and technology adoption will produce consistent estimates of complementarities while allowing for endogenous choices regarding both integration and adoption. Two sets of instruments will be utilized to identify the model: physician labor market conditions for the integration equation and hardware and IT labor costs for the technology adoption component. This approach is adapted from Athey and Stern’s (1998) framework for testing complementarity in organizational design.

Does Information Matter? The Case of Nursing Home Report Cards

Presenter:

David Grabowski

Authors:

David C. Grabowski Jonathan Gruber, Robert J. Town

Chair: Edward Norton; Discussant: Jennifer Troyer Wed June 7, 2006 8:00-9:30 Room 325

Over the last decade, there has been significant growth in the use of public report cards as a mechanism to address information asymmetries on the part of health care consumers. However, the overall welfare implications of report cards are unclear. On the one hand, they may empower consumers to make more informed choices and increase quality competition among providers. However, they may also create disincentives to admit certain patient types (e.g., sicker patients), and they may also increase market power on the part of providers. In the nursing home sector, there have been recent Federal and State initiatives to publicize quality information to consumers. Most significantly, the Federal government introduced the Nursing Home Compare website with a detailed report card on every certified provider in the country. The early rollout of the Federal report cards in a collection of states on a pilot basis along with the various state report card efforts allow us to exploit within-state variation in these policies over time. Using a number of datasets, we assess the overall welfare implications of nursing home report cards. Specifically, we analyze the implications of the introduction of report cards on demand for care, quality, patient mix, private-pay prices, and competition.

The Staffing-Outcomes Relationship in Nursing Homes

Presenter:

Sally Stearns

Authors:

R. Tamara Konetzka, Sally S. Stearns, Jeongyoung Park

Chair: Edward Norton; Discussant: John Nyman Wed June 7, 2006 8:00-9:30 Room 325

The Cost-Quality Relationship: Evidence from Ontario Complex Continuing Care

Presenter:

Walter Wodchis

Authors:

Walter P. Wodchis, Gary F. Teare, Geoff M. Anderson

Chair: Edward Norton; Discussant: Melinda Beeuwkes Buntin Wed June 7, 2006 8:00-9:30 Room 325

The relationship between cost and quality in long-term care has not been carefully explored, yet policy is often made based on assumptions about this relationship. This research examines the relationship between cost performance (cost per weighted patient day) and four quality indicators in Ontario Complex Continuing Care hospital beds. We used five years of data from 99 Ontario facilities from the period 1996 through 2000. Facilities were stratified into high and low categories of cost and quality using quartiles of the indicator distributions. These distributions revealed a marked variability in both cost and quality. Cross-sectional and pooled time-series analyses were also conducted. Over time, cost and quality performance showed a high degree of serial correlation. Reduced costs were associated with lower pressure ulcer prevalence with lower incidence of bladder incontinence, while high costs were associated with high quality assessed as a lower pressure ulcer incidence rate. There was no significant relationship between costs and pain management, prevalence of incontinence, antipsychotic use or the use of physical restraints. The analyses to date indicate opportunities for facilities to improve both cost and quality performance in pressure ulcer management and incontinence care.

The Incidence of the Healthcare Costs of Obesity

Presenter:

Jay Bhattacharya

Authors:

Jay Bhattacharya, M. Kate Bundorf

Chair: Katherine McDonald; Discussant: Jay Bhattacharya Wed June 7, 2006 8:00-9:30 Room 326

The incidence of obesity has increased dramatically in the U.S. Obese individuals tend to be sicker and spend more on health care, raising the question of who bears the incidence of obesity-related health care costs. This question is particularly interesting among those with group coverage through an employer given the lack of explicit risk adjustment of individual health insurance premiums in the group market. In this paper, we examine the incidence of the healthcare costs of obesity among full time workers. We find that the incremental healthcare costs associated with obesity are passed on to obese workers with employer-sponsored health insurance in the form of lower cash wages. Obese workers in firms without employer-sponsored insurance do not have a wage offset relative to their non-obese counterparts. Our estimate of the wage offset exceeds estimates of the expected incremental health care costs of these individuals for obese women, but not for men. We find that a substantial part of the lower wages among obese women attributed to labor market discrimination can be explained by the higher health insurance premiums required to cover them.

JNC VI Had Modest Impact on Antihypertensive Prescribing Patterns in the US between 1993 and 2002

Presenter:

Jun Ma

Authors:

Jun Ma, Ky-Van Lee, Randall Stafford

Chair: Katherine McDonald; Discussant: Jun Ma Wed June 7, 2006 8:00-9:30 Room 326

Objective: Practice guidelines aim to guide physician practice according to the best available evidence. Data are mixed regarding the impact of practice guidelines on physician prescribing. We examined patterns of antihypertensive prescribing between 1993 and 2002 to assess the impact of JNC VI released in 1997. Methods: The 1993-2002 National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS) provided national estimates of clinician-reported antihypertensive prescribing during patient visits to private physician offices and hospital outpatient departments (OPDs). The main outcome measure was the use of antihypertensive drug classes as proportion of visits for adult patients having hypertension as primary diagnosis who were taking any antihypertensive medications (antihypertensive drug visits).
Results: The number of patient visits involving hypertension as the primary diagnosis ranged from 37,777 to 50,173 per annum, of which 62% to 78% received antihypertensive medications. ACE inhibitors (ACEIs) and calcium channel blockers (CCBs) were leading medication choices by physicians in private practice and OPDs for treating hypertension between 1993 and 1997. After the release of JNC VI, the increase in ACEIs seemed to slow down somewhat and the already present decline in CCBs continued. Also, their role as leading antihypertensive drug class was approached or replaced by thiazide diuretics. In 2002, thiazide diuretics accounted for 34% of antihypertensive drug visits in private physician offices and 40% in OPDs, as opposed to 24% in 1993. The use of other diuretics declined by nearly half from 27% of office-based antihypertensive drug visits to in 1993 to 14% in 2002; the degree of decline was smaller in OPDs from 20% to 16%. -blockers increased from a bit over one-fifth of office-based antihypertensive drug visits between 1993 and 1996 to 30% in 1997 but remained plateau thereafter. For visits in OPDs, however, -blockers increased from 19% in 1933 to 24% in 1997 and then to 35% in 2002. Conclusions: Our results suggest that practice guidelines can impact prescribing patterns, but the degree of impact seems modest. A range of other clinical and market factors may mitigate the impact of practice guidelines.

The Effect of Rate Regulation on Access to Supplemental Health Insurance

Presenter:

Kate Bundorf

Authors:

M. Kate Bundorf, Kosali Simon

Chair: Katherine McDonald; Discussant: Kate Bundorf Wed June 7, 2006 8:00-9:30 Room 326

In this paper, we examine the implementation of rating restrictions in the market for privately purchased health insurance supplementing nearly universal, publicly financed Medicare coverage for the elderly in the U.S. Although Medicare is a federal program, private health insurance markets are generally regulated by the states, and during the 1990s, a subset of states adopted different types of rate regulation in this market. We exploit variation in the timing and design of these policies to identify the effects of rate regulation on access to supplemental health insurance. Our analysis is based on data from the 1992-1999 Medicare Current Beneficiary Survey (MCBS). We find that the strongest versions of these laws reduced access to supplemental coverage among low risks and increased access among high risks. We also find evidence of substitution among low risks toward managed care. The results suggest that rate regulation in this market had significant effects on coverage among the elderly.

Dirichlet-Multinomial Regression

Presenter:

Paulo Guimaraes

Authors:

Paulo Guimaraes, Richard C. Lindrooth

Chair: Richard C. Lindrooth; Discussant: Will Manning Wed June 7, 2006 8:00-9:30 Room 335

Weak instruments in nonlinear models with endogenous regressors

Presenter:

Partha Deb

Authors:

Partha Deb

Chair: Richard C. Lindrooth; Discussant: Will Manning Wed June 7, 2006 8:00-9:30 Room 335

Structural Econometric Evaluation of Randomized Clinical Trials

Presenter:

Bart Hamilton

Authors:

Bart Hamilton

Chair: Richard C. Lindrooth; Discussant: Will Manning Wed June 7, 2006 8:00-9:30 Room 335

ASHEcon

3rd Biennial Conference: Cornell on June 20-23 2010

Welcome to ASHEcon

The American Society of Health Economists (ASHEcon) is a professional organization dedicated to promoting excellence in health economics research in the United States. ASHEcon is an affiliate of the International Health Economics Association (iHEA). ASHEcon provides a forum for emerging ideas and empirical results of health economics research.