OBJECTIVES: Although there is substantial evidence of declining prevalence of disability among the older population during the late 1980s and 1990s, evidence on trends in the underlying dynamics of disability is lacking. For this study, we estimated models of transitions between discrete disability and vital states that incorporated simple linear time trends. METHODS: We analyzed data from the 1982-1994 interviews of the New Haven Established Populations for Epidemiologic Studies of the Elderly study and used three alternative measures of disability status. We estimated separate models of disability prevalence and disability transitions by gender. RESULTS: Eleven of 12 estimated trends in transition rates were statistically significant. For men and women, and for three alternative disability indicators, we found downward trends in rates of both onset of and recovery from disability among people aged 75 and older. We did not find any consistent pattern of trends in disability among those aging into the 75 and older group during this period. DISCUSSION: Our findings are consistent with declining population-level disability prevalence only if any downward trend in onset outweighs the downward trend in recovery. These findings are also consistent with a trend toward more severe disability problems among the disabled population.
OBJECTIVES: Although there is substantial evidence of declining prevalence of disability among the older population during the late 1980s and 1990s, evidence on trends in the underlying dynamics of disability is lacking. For this study, we estimated models of transitions between discrete disability and vital states that incorporated simple linear time trends. METHODS: We analyzed data from the 1982-1994 interviews of the New Haven Established Populations for Epidemiologic Studies of the Elderly study and used three alternative measures of disability status. We estimated separate models of disability prevalence and disability transitions by gender. RESULTS: Eleven of 12 estimated trends in transition rates were statistically significant. For men and women, and for three alternative disability indicators, we found downward trends in rates of both onset of and recovery from disability among people aged 75 and older. We did not find any consistent pattern of trends in disability among those aging into the 75 and older group during this period. DISCUSSION: Our findings are consistent with declining population-level disability prevalence only if any downward trend in onset outweighs the downward trend in recovery. These findings are also consistent with a trend toward more severe disability problems among the disabled population.