Anxiety is an independent predictor of disease activity at three months after initiating treatment with disease modifying antu-rheumatic drugs (DMARDs) in early arthritis patients

Background/Purpose: To explore the additional effect of psychosocial factors on the Disease Activity Score (DAS) in early arthritis patients three months after initiating treatment with disease modifying anti-rheumatic drugs (DMARDs). Methods: Sample: 515 patients with recent-onset arthritis in a single-blinded clinical trial named ‘Treatment in the Rotterdam Early Arthritis CoHort (tREACH)’. Patients were included who had a high probability (>70%) of progressing persistent arthritis and were randomised into three induction treatment strategies. Data were collected on demographics, clinical and psychosocial characteristics, including questionnaire data on coping style, fatigue, depression, anxiety, social support and locus of control. Questionnaires were sent at baseline to patients by post. The effect of baseline psychological characteristics on the DAS at three months after initiation of treatment was evaluated using a multivariate linear regression model including known factors: treatment strategies, baseline DAS, age, sex and rheumatoid factor or anticitrullinated protein autoantibodies positivity. Results: 281 patients (91 men (32%), 190 women (68%); mean (SD) baseline DAS: 3.4 (0.96)) were included in the analysis. After backwards selection, but forcing the known factors into the model, anxiety was identified as an independent predictor for DAS (β=0.18; p=0.002), while coping with pain reached borderline significance (β=0.11; p=0.07). Anxiety explained 3.5% of the variation and anxiety and coping with pain together explained 4.5% of the variation of DAS after three months. Conclusion: Our results suggest that especially anxiety is a predictor of disease activity in early arthritis patients three months after initiation of treatment with DMARDs. Coping with pain might also be an important predictor. Physicians should address these factors when initiating treatment with DMARDs to increase therapeutic effectiveness.