Baseline predictors of fatigue and persistent fatigue in rheumatoid arthritis: A longitudinal observational study.

Objectives: To determine factors associated with fatigue in patients with rheumatoid arthritis (RA), and to identify baseline predictors of persistent fatigue at 12 months of follow-up.

Methods: We enroled patients with RA fulfiling the 2010 American College of Rheumatology/European League Against Rheumatism criteria. Fatigue was assessed using the Arabic version of the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F). Using univariate and multivariate analyses, we examined baseline variables associated with fatigue and persistent fatigue (if the FACIT-F score was less than 40 at baseline and 12 months of follow-up).

Results: We included 100 RA patients of whom 83% reported fatigue. At baseline, the FACIT-F score was significantly associated with older age (p = 0.007), pain (p < 0.001), global patient assessment (GPA) (p < 0.001), tender joint count (TJC) (p < 0.001), swollen joint count (p = 0.003), erythrocyte sedimentation rate (ESR) (p < 0.001), disease activity score (DAS28 ESR) (p < 0.001), and health assessment questionnaire (HAQ) (p < 0.001). At 12 months of follow-up, the percentage of patients who reported persistent fatigue was 60%. The FACIT-F score was significantly associated with age (p = 0.015), symptom duration (p = 0.002), pain (p < 0.001), GPA (p < 0.001), TJC (p < 0.001), C-Reactive Protein (p = 0.007), ESR (p = 0.009), DAS28 ESR (p < 0.001), and HAQ (p < 0.001). Pain was an independent baseline predictor of persistent fatigue (OR = 0.969 (95% CI [0.951-0.988]), p = 0.002).

Conclusions: Fatigue is a frequent symptom in RA. Pain, GPA, disease activity and disability were associated with fatigue and persistent fatigue. Baseline pain was the only independent predictor of persistent fatigue.