Disease, disability, and age in cognitively intact seniors: results from the Canadian Study of Health and Aging

Abstract

Background: Many diseases have been identified as risk factors for disability in the elderly. This report contrasts disability in the old-old (85 years of age or older, 85+) with younger seniors (65-84 years of age) and examines whether diseases have an equivalent impact on the two groups.

Methods: Subjects were 603 cognitively intact community residents 65 years of age and older from 10 Canadian provinces. The purpose of the analysis was to try to isolate the effects of age and nondementing disease on function. Frequency of disease and functional disabilities was calculated. Logistic regression was used to determine significant explanatory variables for moderate, severe, or total disability and for specific disabilities.

Results: Nearly twice as many of the cognitively intact 85+ had functional disabilities compared to those 65-84 years of age. In the 85+, increasing age was the only significant explanatory variable for moderate, severe, or total disability and for problems with walking, showering, shopping, getting to places out of walking distance, and preparing meals. Diseases were also significant explanatory variables for functional disabilities, particularly in the 65-84 age range. An increase in the proportion with functional disability was found with increasing age even in those without the relevant disease risk factors.

Conclusions: Disease prevention would only be partially effective in avoiding disability in the very old because disability occurred even in those without explanatory disease.