Chronic disease and severe disability among working-age populations

Background: Recent work has shown that rates of severe disability, measured by the inability to perform basic activities of daily living, have been rising in working age populations. At the same time, the prevalence of important chronic diseases has been rising, while others falling, among working age populations. Chronically ill individuals are more likely than others to have activity of daily living limitations. Objective: We examine the extent to which chronic disease trends can explain these disability trends. Data: We use nationally representative survey data from the 1984-1996 National Interview Survey, which posed a consistent set of questions regarding limitations in activities of daily living over that period. Methods: We decompose trends in disability into 2 parts-1 part due to trends in the prevalence of chronic disease and the other due to trends in disability prevalence among those with chronic disease. Results: Our primary findings are that for working age populations between 1984 and 1996: (1) disability prevalence fell dramatically among the nonchronically ill; (2) rising obesity prevalence explains about 40% of the rise in disability attributable to trends chronic illness; and (3) rising disability prevalence among the chronically ill explains about 60% of the rise in disability attributable to trends in chronic illness. Conclusions: Disability prevention efforts in working age populations should focus on reductions in obesity prevalence and limiting disability among chronically ill populations. Given the rise in disability among these population subgroups, it is unclear whether further substantial declines in elderly disability can be expected.