Sex differences in functional limitation level and the role of socioeconomic factors

Abstract

Abstract Background Women are more likely to have functional limitations than men, partly due to socioeconomic disadvantage. As much of this research is based on dichotomised measures of limitation, how sex differences vary by level of limitations remains unclear. The aim of our study was to examine sex differences in functional limitations in people born between 1895 and 1960, with attention to the role of socioeconomic factors and level of limitations. Methods Longitudinal data on limitations in basic/instrumental activities of daily living (ADL/IADL) and mobility activities were drawn from studies in 14 countries. For ADL, IADL, and mobility activities, participants were grouped into limitation levels based on number of limited activities (0, 1, 2, or ≥ 3). Sex differences in limitations in four birth cohorts (1895-1929, 1930-1938, 1939-1945, 1946-1960) were analysed before and after adjustment for socioeconomic factors using mixed effects ordinal logistic models. Findings Among 62,375 participants, sex differences in IADL and ADL limitations (≥1) were minor after adjustment for socioeconomic factors (sex difference in probability of limitations (female - male) age 75, 1895-1929 cohort for IADL=3.7% (95% CI 2.6, 4.7) before and 1.7% (1.1, 2.2) after adjustment; ADL=3.2% (2.3, 4.1) before, 1.4% (0.9, 1.8) after). Sex differences remained for mobility (16.1% (14.4, 17.7) before, 14.3% (12.7, 15.9) after). At older ages, women were more likely to have ≥3 IADL or mobility limitations, while men were more likely to have 1 to 2. Conclusions Socioeconomic factors explain the majority of sex differences in IADL and ADL limitations but not mobility, with women reporting greater mobility limitations than men starting in middle age. Our findings suggest sex differences in mobility limitations from middle age might be important targets for future study and interventions. Key messages Sex differences in disability vary considerably between disability measures. Comprehensive assessment of sex differences in disability should consider disability severity across different measures. Findings suggest there may be fewer sex differences in disability in the future with progressively decreasing socioeconomic disparities between men and women.