The burden of pain in rheumatoid arthritis: Impact of disease activity and psychological factors.

BACKGROUND: Pain remains a prevalent symptom for rheumatoid arthritis (RA) patients despite a wide therapeutic choice. The objective of this study was to provide a multidimensional evaluation of pain. METHODS: A total of 295 RA patients from 7 French rheumatology centres were enrolled in a cross-sectional study. Patients completed a chronic pain assessment questionnaire approved by the French National Authority for Health, the health assessment questionnaire (HAQ) as well as depression and anxiety scales (HAD, Beck Depression Inventory, STAI). Disease activity (DAS28) and ESR were recorded. A multivariate descriptive analysis was undertaken using principal component analysis (PCA). RESULTS: 38.4% of patients had a pain score > 40 mm/100, although 83% were on biological treatment and 38.7% were in remission based on the RA activity score. The PCA analysis found four axes representing 70% of total variance. The axes, per cent of variance and variables represented were as follows: (a) axis 1, 41% variance, anxiety and depression scores, sensory and affective qualifier score, HAQ and pain impact on daily life; (b) axis 2, 13% variance, disease activity score (DAS28) and pain relief with current treatment; (c) axis 3, 9% of variance, RA duration and radiographic score and (d) axis 4, 6% of variance, DAS28 and ESR. Moderate to severe pain was significantly associated with axes 1 and 2. CONCLUSIONS: Despite a high proportion of patients on biological treatments, 38.4% of patients continue to experience moderate to severe pain. Pain is associated with the RA activity score, but also with the depression and anxiety scores. SIGNIFICANCE: Substantial proportion of rheumatoid arthritis (RA) patients still experiences relevant pain, although more than 80% on biological treatment. Pain is primarily associated with anxiety and depression scores and with disease activity score. These findings highlight the need to assess patients' mental well-being alongside. Clinical measures of disease activity to better manage pain and guide treatment decisions.