Analysis of the association of fatigue with clinical and psychological variables in a series of 371 Brazilian patients with rheumatoid arthritis

Objectives: Fatigue is a highly subjective and extremely common symptom in patients with rheumatoid arthritis although it is difficult to characterize and define. The aim of this study was to assess fatigue in a cohort of Brazilian patients, and to analyze the relationship between fatigue and disease-specific variables. Methods: 371 Brazilian patients diagnosed with rheumatoid arthritis according to the 1987 American College of Rheumatology classification criteria were prospectively investigated. Demographic, clinical and laboratorial data were obtained from hospitals records. The number of painful joints, bone mass index, disease duration, quality of life, functional capacity, anxiety and depression were recorded. Fatigue was evaluated using the subscale of Fatigue Assessment of Chronic Illness Therapy (FACIT-FATIGUE scale). Results: The median fatigue score was 42.0 (10.0), negatively correlated with functional capacity (-0.507; P < 0.001), anxiety and depression (-0.542 and -0.545; P < 0.001 respectively), and predominantly with physical domain of Short Form 36-item quality of life questionnaire (SF-36P: 0.584; P < 0.001). The scores were not associated with the erythrocyte sedimentation rate (-0.118; P < 0.05), C-reactive protein (-0.089; P < 0.05), disease activity (-0.250; P < 0.001) or the number of painful joints (-0.135; P < 0.01). Confidence interval of 95% was applied for all measures. Conclusions: In this series of Brazilian patients with rheumatoid arthritis, we suggest a new significance for fatigue complains as an independent parameter not related with number of painful joints, disease or inflammatory activity scores. Psychological and functional impairments appear to be more related to fatigue. Additional studies and inclusion of standard measures for monitoring fatigue complains are required. (C) 2014 Sociedade Brasileira de Reumatologia. Published by Elsevier Editora Ltda. All rights reserved.