Comparison of physical and social risk-reducing factors for the development of disability in older adults: a population-based cohort study

BACKGROUND: Considerations of modifiable risk factors for the development of disability in older age have traditionally focused on physical activity. However, there is increasing evidence that psychological, social, and cognitive factors also help to maintain functional independence. This study compared the protective associations between physical and social activities and disability onset. METHODS: We analysed data from 5434 adults aged 50+ years tracked biennially from 2004/2005 to 2016/2017, measuring self-reported difficulty in carrying out any basic activities of daily living (ADLs) or instrumental ADLs. Exposures included mild, moderate and vigorous physical activity, frequency of socialising with friends/family, cultural engagement (eg, going to the theatre/museums/concerts), and participation in community groups. RESULTS: Over the 12-year follow-up, 1945 adults developed disability. Using Cox proportional hazards regression models adjusted for all identified demographic and health-related variables, vigorous exercise or activity once a month or more (HR 0.82, 95% CI 0.71 to 0.96), moderate exercise or activity more than once a week (HR 0.81, 95% CI 0.67 to 0.97) or cultural engagement once or twice a year or more (HR 0.84, 95% CI 0.73 to 0.97) were associated with a lower hazard of developing disability. Other exposures did not show independent protective associations. Results were robust to sensitivity analyses considering reverse causality and exploring the potential confounding role of time-invariant factors, such as socioeconomic status. CONCLUSION: These results suggest the importance of either developing multimodal interventions to protect against disability and promote healthy ageing or promoting greater physical and social engagement with existing community activities among older adults.