Longitudinal study of determinants of dependence in an elderly population.

OBJECTIVES: To describe those factors, from the host of initial measures in ambulatory, independent older men and women, that were determinants of becoming dependent over an 8-year follow-up. DESIGN: Initial measures in a cohort of independent older adults were used in logistic regression to describe the determinants of becoming dependent at the 8-year follow-up. SETTING: London, Ontario. PARTICIPANTS: Three hundred seventy-three men and women aged 55 to 86. MEASUREMENTS: Initial variables included body size, presence of chronic disease, maximal oxygen uptake (VO2max), strength, flexibility, walking pace, and leisure time physical activity. RESULTS: An 8-year follow-up of 297 participants identified 43 as dependent. Logistic regression showed age, presence of disease, and VO2max (cardiorespiratory fitness) at baseline to have significant odds ratios related to the outcome of becoming dependent. Controlling for other factors, a lower VO2max increased the odds of dependence by 14% for each mL/kg.min. CONCLUSION: Lower cardiorespiratory fitness was a significant determinant of becoming dependent in an 8-year follow-up of older adults. Initiatives to encourage physical activity in older adults should emphasize exercise, such as brisk walking, to maintain or improve cardiorespiratory fitness.