Functional Capacity and Difficulties in Activities of Daily Living From a Cross-National Perspective

Objectives: This study investigated whether physical and cognitive functioning predicts developing difficulties in basic or instrumental activities of daily living (ADL/IADL), and whether country-level factors moderated the associations. Methods: 69,227 adults aged 50+ from 19 countries were followed for up to 14 years. Cox regression and meta-regression analyses were used. Results: Higher grip strength was associated with a 45% lower risk of developing ADL limitations and a 47% lower risk of IADL limitations. The corresponding values were 22% and 23% for peak flow, 20% and 23% for word recall, and 20% and 24% for temporal orientation. The associations were similar and statistically significant in most countries, but some associations were weaker in countries with lower GDP and lower service coverage. Discussion: Good physical and cognitive functional capacity protects from ADL and IADL limitations consistently across Western countries. The associations may be stronger in countries with more resources.