The prospective association between psychological distress and disease activity in rheumatoid arthritis: a multilevel regression analysis

Background Cross-sectional associations suggest a mutual impact of disease activity and psychological distress in rheumatoid arthritis (RA), but a prospective association has not been established. Objective To examine concurrent and prospective associations between psychological distress and disease activity. Methods Patients with RA (N=545, disease duration <= 1 year, age 18-83 years, 69% female, 64% rheumatoid factor (RF) positive) were monitored for 5 years. The Thompson joint score and erythrocyte sedimentation rate were assessed every 6 months. Depressed mood and anxiety were measured every 12 months. Multilevel regression analysis was used. RF positivity, age and female sex were included as covariates. Results Concurrent levels of psychological distress and disease activity were positively associated (p <= 0.04). Prospectively, depressed mood was associated with disease activity levels 6 months later (p <= 0.04). The Thompson joint score was associated with psychological distress levels 6 months later (p=0.03) and also with an increase in depressed mood over the subsequent 6 months (p=0.02). No other significant prospective associations were found (p >= 0.07). Conclusions Psychological distress and disease activity are positively associated when measured at the same time as well as when measured 6 months apart. While some support was found for the idea that a higher level of disease activity is a risk factor for an increase in psychological distress, the results do not support the notion that psychological distress is a risk factor for future exacerbation of disease activity.