Ageing and the relationship between functional status and self-rated health in elderly men

Functional status (measured as functional limitations or disabilities) is an important determinant of self-rated health in the elderly. Several issues which are not yet clear in this association are addressed in this study: (i) the modifying effect of age on the association; (ii) the effect of recent changes in disability level on the current level of self-rated health, and (iii) the effect of functional limitations on self-rated health, independent of disabilities. Data were derived from the 1990, 1993 and 1995 surveys of the Zutphen Elderly Study, a longitudinal health study in men born between 1900 and 1920. Analyses of repeated measurements were performed with self-rated health as dependent variable and disabilities, functional limitations, age, survey year, and interaction terms as independent variables. Odds ratios were calculated from these models. Men with disabilities in instrumental activities of daily living had no different health ratings than men without disabilities. Those with disabilities in mobility and basic activities of daily living, however, had an odds ratio on poor self-rated health of 4.7 (95% confidence interval: 2.7-7.9) and 8.9 (4.6-17.1) respectively. This association became weaker with increasing age, leading to an absence of a significant association in the oldest group. The current level of self-rated health was only associated with the current level of disabilities. Information on previous levels of disabilities did not contribute to current self-rated health. Functional limitations had a small, but significant, effect on self-rated health when disabilities were taken into account. This study helps in enhancing insight in the complex relationship between functional status and self-rated health in the elderly.