Accounting for changes in morbidity among the non-elderly in the U.S.
- Presenter:
Chair: Jeffrey Pyne; Discussant: David Cutler Mon June 5, 2006 17:15-18:45 Room 309
Background and objective: Evidence suggests that disability among the elderly in the U.S. has declined by 1-2 percent per year during the past several decades, but it is unclear whether disability has also decreased among the non-elderly population. The purpose of this paper is two-fold: (1) to estimate trends in morbidity among the non-elderly using more recent national surveillance data; (2) to determine if changes in disease severity or disease prevalence are responsible for these trends.
Methodology: We used data from the National Health Interview Survey (NHIS), a yearly nationally representative probability sample of the non-institutionalized U.S. population. We estimated trends in disability among individuals aged 18-64 using the 1997-2004 NHIS, and conducted decomposition analysis to determine the degree to which these changes are influenced by changes in prevalence of chronic diseases (including cardiovascular disease, diabetes, and hypertension) and changes in disease severity. Disability was defined as having personal-care or routine-needs limitations. We also looked at the proportion of individuals whose self-reported health is poor or fair. The analysis used a complex sample survey method with controls for age, sex, race/ethnicity, employment, and education.
Results: The data show that disability among the non-elderly population increased over 20 percent between 1997 and 2004 (2.2% in 1997; 2.4% in 2004). The proportion of individuals whose self-reported health status was fair or poor also rose over 14 percent during the same period (9.1% in 1997; 10.4% in 2004). It is estimated that the increased prevalence of cardiovascular disease, hypertension and diabetes among those aged 45-64 accounts for about 15 percent of the increase in disability and 20 percent of the lower self-reported status. There is little evidence of increased severity among individuals with these conditions.
Conclusions: Our study found that, after accounting for demographic and socioeconomic changes, disability among the non-elderly has increased in the past several years. The proportion of those who report poor or fair health status has also risen. The results also show that, in contrast to what has been suggested for the elderly, increased chronic disease prevalence accounts almost all of worsening disability and self-reported health status. The findings highlight the importance of primary prevention of chronic diseases in reducing morbidity among the middle-aged population.
