Physical and psychosocial correlates of severe fatigue in rheumatoid arthritis

Objectives. Fatigue is a frequently experienced and patient-relevant complaint in RA. Disease activity, anaemia and pain are regarded as disease-related factors that may lead to fatigue in RA. However, psychosocial factors may also play a role in maintaining severe fatigue. The objectives of this study were to determine the prevalence of severe fatigue in RA patients, to study patient perceptions of fatigue and to determine which disease-related factors and psychosocial factors are independently associated with fatigue severity. Methods. For this study consecutive RA outpatients were enrolled (n = 228). The patients filled out questionnaires regarding fatigue using the Checklist Individual Strength (CIS), including psychosocial factors, pain and disability. The clinical data that were collected included ESR, CRP, haemoglobin level and 28-joint disease activity score (DAS-28). Chunk-wise backward linear regression was used for analysis. Results. Severe fatigue (CIS >= 35) was experienced by 42% of the RA patients, and they perceived their fatigue as frustrating or exhausting. The severely fatigued RA patients scored worse on all measured psychosocial items, compared with patients without severe fatigue. Pain severity, role functioning, depressive mood, self-efficacy on fatigue, worrying, helplessness and non-restorative sleep were the factors most strongly associated with fatigue level. Conclusions. A considerable proportion of RA patients had severe fatigue, with fatigue levels similar to chronic fatigue syndrome. Fatigue in RA was related to pain and functioning, not inflammation, as disease-related factors and to several psychosocial factors including coping and cognitions concerning fatigue.