Analysis of disability-free life expectancy over the lifespan: From maturity to old age

Objective: To determine the life stages in which disability-free life expectancy is shortened before the age of 70 years. Method: A retrospective longitudinal analysis was carried out in a cohort of 1,286 non-institutionalized people aged from 70 to 74 years old living in metropolitan areas. Disability was measured by instrumental and basic activities of daily living. Disability-free life expectancy was calculated. The Kaplan-Meier method was used to calculate survival probabilities. Results: The incidence of basic disability increased from 50 to 54 years old and progressively accelerated until the age of 65-69 years old when the probability of instrumental disability was slightly higher among men than among women (0.23 in men versus 0.19 in women). Disability-free survival was lower among women than among men both for all types of disability (LogRank = 5.80; p = 0.016) and for basic disability (LogRank = 4.315; p = 0.038). Conclusions: This study reveals the importance of instrumental disability for domestic tasks among older men. Women had a lower probability of disability-free survival and were more likely to be affected by any type of disability as well as by basic disability. For both genders, there is a slight decrease in disability-free survival from the age of 40 to 60 years. From this age onwards, this decrease markedly accelerates. © 2011 SESPAS.