Depressive Symptoms and Physical Activity Mediate the Adverse Effect of Pain on Functional Dependence in Patients With Arthritis: Evidence From the Canadian Longitudinal Study on Aging

Phys Ther. 2025 Oct 3:pzaf120. doi: 10.1093/ptj/pzaf120. Online ahead of print.

ABSTRACT

IMPORTANCE: Arthritis is a chronic condition affecting hundreds of millions of people worldwide, often leading to pain and functional limitations.

OBJECTIVE: This study aimed to investigate the direct and indirect effects of pain on functional dependence in individuals with arthritis. Depressive symptoms and physical activity were examined as potential mediators of this relationship.

DESIGN: This study was a longitudinal cohort study.

SETTING: The study setting included community-dwelling adults participating in the Canadian Longitudinal Study on Aging.

PARTICIPANTS: This study included a total of 6972 participants with arthritis including 4930 with osteoarthritis and 694 with rheumatoid arthritis.

EXPOSURE: The exposure was the usual presence of pain or discomfort at baseline, with depressive symptoms (CESD-10) and physical activity (PASE) tested as mediators.

MAIN OUTCOME AND MEASURE: The main outcome was functional dependence in activities of daily living (ADL) and instrumental activities of daily living (IADL) at follow-up, measured with a modified version of the Older Americans’ Resources and Services Multidimensional Functional Assessment Questionnaire (OARS).

RESULTS: Baseline pain was positively associated with depressive symptoms (b = 0.356 [95% CI = 0.310 to 0.402]) and negatively associated with physical activity (b = -0.083 [95% CI = -0.125 to -0.042]). Functional dependence at follow-up was significantly predicted by baseline pain (log OR = 0.607 [95% CI = 0.261 to 0.952]), depressive symptoms (log OR = 0.358 [95% CI = 0.184 to 0.533]), and physical activity (log OR = -0.598 [95% CI = -0.818 to -0.378]). Mediation analysis showed that 23.3% of the total effect of pain on functional dependence was accounted for by the indirect effect through depressive symptoms (16.2%), physical activity (6.3%), and their serial combination (0.8%).

CONCLUSIONS: The presence of pain at baseline was associated with higher odds of functional dependence in basic and instrumental activities of daily living after a mean follow-up period of 6.3 years, with depressive symptoms and lower physical activity acting as mediators.

RELEVANCE: The findings highlight the need for arthritis care to extend beyond pain management by incorporating strategies that address depressive symptoms and promote physical activity to preserve functional independence.

PMID:41042239 | DOI:10.1093/ptj/pzaf120