Pain Phenotypes and Falls in Older Adults: Cross-Sectional Associations by Social Engagement

Pain is commonly associated with falls in older adults, but the associations between different pain phenotypes and falls remain unclear. It is also uncertain whether social engagement is associated with modification of these associations. This study examined the cross-sectional associations between pain phenotypes and falls in older adults and assessed whether these associations varied by social engagement.

We used data from the 2018 wave of the China Health and Retirement Longitudinal Study (CHARLS) to categorize participants into four pain phenotypes with a rule-based algorithm. Multivariable logistic regression was used to examine associations between pain phenotypes and falls, and interaction with social engagement was assessed on both multiplicative and additive scales. Subgroup and sensitivity analyses were conducted to test robustness.

Among participants, 19.6% reported falling in the past year. Fall risk was higher in women, rural residents, and those with limited social engagement. Compared with no pain, the adjusted odds ratios for falls were 1.26 for mild localized pain, 1.40 for moderate localized pain, and 2.12 for widespread multi-site pain. Social engagement was associated with differences in the association between pain phenotypes and falls, with a significant multiplicative interaction (p = .001) and a negative additive interaction for widespread multi-site pain.

Widespread multi-site pain was associated with higher odds of falls in older adults, and the association between widespread multi-site pain and falls differed by level of social engagement. These findings support the importance of incorporating both pain phenotype assessment and social factors into fall-prevention strategies, while longitudinal studies are needed to clarify the temporal and causal relationships among pain, social engagement, and falls.