Insurance Matters: Prevalence and Costs of Potentially Preventable Hospitalizations in Tennessee by Insurance Type
- Presenter:
Chair: Ryan Mutter; Discussant: Ryan Mutter Mon June 5, 2006 17:15-18:45 Room 213
Purpose: This paper analyzes Tennessee hospital discharge records and uses insurance type as a factor to predict the likelihood of hospitalization for an ambulatory care-sensitive (ACS) condition.
Background: ACS conditions are those for which timely and effective outpatient care can potentially prevent the need for hospitalization. High incidence of preventable hospitalizations such as asthma, diabetes, hypertension and congestive heart failure may be indicative of underlying problems with access to primary care or deficiencies in outpatient care management. Analysis of preventable hospitalizations can thus provide information for health system evaluation. TennCare is Tennessee’s experimental Medicaid managed care program that began in 1994. An overarching goal of this reform model was to deliver prevention-centered longitudinal care to reduce inappropriate use of inpatient care. The resulting savings, it was theorized, could then be used to expand insurance coverage. However, the expected outcome of better use of primary care of this $8.4 billion program that covers 1 in every 4 Tennesseans has never been investigated.
Hypotheses: We will test two hypotheses. The first is that patients insured by TennCare are more likely to be admitted for ACS conditions than patients insured by other insurance types after controlling for race, age, gender, and co-morbidities. The second hypothesis is that the likelihood of ACS hospitalization varies among the different TennCare Managed Care Organizations (MCOs), with patients insured by nonprofit, academic-medical-center-affiliated MCOs having a lower likelihood of ACS hospitalization than those insured by other MCOs.
Data Sources: The primary source is the Hospital Inpatient Discharge Data System (HDDS) maintained by the Tennessee Department of Health for 1997-2002. HDDS receives information from UB-92 forms on all inpatient discharges in Tennessee. Each form contains information on patient diagnoses, procedures performed, charges, and selected patient demographics. We will also use county-level Area Resource File data to describe the environments in which patients live.
Methodology: We will use the AHRQ definition of Potentially Avoidable Hospitalizations which include those for 16 specific ACS conditions. There will be two dependent variables for each of the two hypotheses: a dummy variable with 1 signifying an ACS admission and 0 otherwise; the total charges of the admission. The key independent variable for the logistic regressions is a categorical variable representing insurance type (TennCare, Medicare, Private insurance, Self Pay, etc.). Control variables include patient demographics such as age, gender, race, patient risk strata that consist of principal and co-morbidity diagnoses, and county characteristics such as population density, percent poverty, supply of primary care physicians per 100,000 population. In the second regression analysis with the hospital charges as the dependent variable, a dummy variable representing whether the admission is for an ACS condition or not will be added.
Potential Contribution: Little is known about TennCare’s effectiveness in the provision and deployment of primary care. If significance differences in the prevalence and expenditures of primary care-sensitive hospitalizations are found between TennCare and other insurance types after controlling for confounding factors, the results will shed new light on the performance of TennCare as a model of public-sector Medicaid reform.
