Prevalence of disability in three birth cohorts at old age over time spansof 10 and 20 years

The prevalence of disability at the age of 75 + measured by the Katz Index of Activities of Daily Living (ADL) was compared among three birth cohorts: those born less than or equal to 1903 (n = 348), those born less than or e qual to 1913 (n = 586), and those born less than or equal to 1923 (n = 758) . Significant risk factors for disability were female sex and age; the coho rt effect was not significant. The prevalence rates of disability were 29.0 % (95% CI 24.2-33.8), 34.8% (30.9-38.7), and 28.8% (25.5-32.0) for the firs t, second, and third cohorts. In the age group 75-79 years the rates were 2 0.1% (95% Cl 13.8-26.4), 25.5% (20.2-30.7), and 14.4% (10.6-18.1). The chan ge was due to the declining disability of women. The distributions in the t hree cohorts based on the numbers of ADL limitations did not differ. As far as the whole aged populations were concerned, longer life was not accompan ied by improving health. (C) 2001 Elsevier Science Inc. All fights reserved .