Longitudinal association between social capital and functional disability in a cohort of community dwelling older adults

This study aimed to investigate the association between social capital and functional disability, based on a longitudinal perspective, using data from the cohort of older adults from Bambui, Minas Gerais State, Brazil. The baseline of this study was composed of all surviving and disability-free - up until the seventh year of follow- up (2004) - older adults who were followed up until 2011. The outcome variable was functional disability for basic activities of daily living (ADL) and instrumental activities of daily living (IADL), separately analyzed. Social capital was the exposure of interest, measured through its cognitive (cohesion and social support) and structural (social participation and satisfaction with the neighborhood) components. Sociodemographic variables, health conditions, and lifestyle habits were used for adjustment purposes, and the occurrence of death was considered a competitive event. The hypothesis of association between social capital and functional disability was tested using the competing risk model, which provides hazard ratios (HR) and a 95% confidence interval (95%CI). After multivariate analysis, social capital - in its structural component - was associated with functional disability. Older adults who were dissatisfied with the neighborhood had a higher risk of developing functional disability for IADL (HR = 2.36; 95%CI: 1.31-4.24), in relation to their counterparts. This study results suggest that functional disability is associated with aspects other than health, evidencing the need for the development of policies and interventions that support aspects related to the physical and social environment in which older adults live.