Rethinking mobility: Life space outperforms physical activity as a correlate of health outcomes among older adults in Singapore

Objective Physical activity and life space are modifiable behavioral factors relevant to preventive medicine. While both are associated with health outcomes in older adults, their distinct contributions remain unclear. This study examined their associations with self-rated health and objectively measured physical performance, and tested whether effects on self-rated health were mediated by physical performance. Methods We recruited 1118 community-dwelling older adults aged ≥50 years in Singapore between April 2022 and August 2023. Participants completed the University of Alabama at Birmingham's Life Space Assessment, the International Physical Activity Questionnaire-Short Form, and the EuroQol-Visual Analogue Scale. Physical performance was assessed using the Short Physical Performance Battery and three additional performance-based tests. Structural regression modeled direct effects on self-rated health and indirect effects via physical performance. Results Life space emerged as a stronger predictor of both outcomes. It had both direct and indirect effects on self-rated health, whereas physical activity had only an indirect effect via physical performance. Conclusions These findings suggest that life space may serve as a complementary or alternative indicator to traditional physical activity metrics for preventive medicine, supporting early identification and monitoring of functional decline in older adults.