Positive Affect is Associated with Better Physical Function in Early Rheumatoid Arthritis

OBJECTIVE: This study examined the association between positive affect and physical function in individuals with early rheumatoid arthritis (RA). METHODS: We analyzed baseline data from 129 adults with early RA (persistent joint symptoms for ≤ 24 months) and active disease enrolled in the Central Pain in RA 2 (CPIRA-2) study. Patient-reported outcome measures assessed positive affect (using the positive affect subscale of the Positive and Negative Affect Schedule [PANAS]), physical function, pain intensity, and other psychological factors. We constructed linear regression models to estimate unadjusted and adjusted cross-sectional associations between positive affect and physical function. Adjusted models controlled for age, sex, body mass index, swollen joint count, symptom duration, pain intensity, and depression. Further analyses were constructed to evaluate whether pain intensity modified the relationship between positive affect and physical function. RESULTS: Greater self-reported positive affect (β for every 5-unit increase = 1.4, p = 0.002) was associated with better physical function independent of pain intensity and depressive symptoms. In additional analyses, pain intensity significantly modified this relationship (interaction β = -0.5, p = 0.001), the positive association between positive affect and physical function weakened as pain intensity increased. Findings remained consistent when controlling for alternative negative affect measures (pain catastrophizing and anxiety) in place of depression. CONCLUSION: Positive affect was independently associated with self-reported physical function in early RA, suggesting that resilience-related psychological processes may contribute to functional outcomes during the early stages of disease. Interventions targeting positive emotional well-being may complement RA treatment approaches aimed at preserving and improving physical function.