title: Patients receiving anti-TNF therapies experience clinically important improvements in RA-related fatigue: results from the British Society for Rheumatology Biologics Register for Rheumatoid Arthritis.
abstract: OBJECTIVE
  Pro-inflammatory cytokines such as TNF-α are important in the pathogenesis of fatigue in conditions such as RA. This study aimed to determine whether fatigue improved in a cohort of RA patients with clinically relevant fatigue commencing anti-TNF-α therapy and, if so, to identify predictors of improvement.
  
  
  METHODS
  Participants recruited to a long-term observational cohort study (the British Society for Rheumatology Biologics Register for RA) provided information on fatigue using the 36-item Short Form Health Survey (SF-36) vitality subscale. The prevalence of severe baseline fatigue (SF-36 vitality ≤12.5) was calculated and improvements, considered as (i) absolute values and (ii) improvement from severe to non-severe fatigue (SF-36 vitality >12.5), were examined 6 months subsequently. A comprehensive set of putative predictors of fatigue improvement were evaluated using multivariable logistic regression.
  
  
  RESULTS
  In 6835 participants the prevalence of severe baseline fatigue was 38.8%. Of those with severe fatigue, 70% reported clinically relevant improvement and 66% moved to the non-severe fatigue category (i.e. improvers). The mean change for improvers was three times the minimum clinically important difference for improvement (33.0 U). Independent baseline predictors of improvement were female sex [odds ratio (OR) 1.3 (95% CI 1.1, 1.7)], not being unemployed due to ill health [OR 1.5 (95% CI 1.2, 1.7)], low disability [OR 1.2 (95% CI 1.001, 1.5)], seropositivity [OR 1.2 (95% CI 0.98, 1.4)], not using steroids [OR 1.2 (95% CI 1.03, 1.5)], no history of hypertension [OR 1.4 (95% CI 1.1, 1.6)] or depression [OR 1.3 (95% CI 1.1, 1.5)] and good mental health [SF-36 mental health subscale >35; OR 1.4 (95% CI 1.2, 1.7)].
  
  
  CONCLUSIONS
  Fatigued RA patients reported substantial improvement in their fatigue after commencing anti-TNF-α therapy. Further, a number of clinical and psychosocial baseline factors identified those most likely to improve, supporting future stratified approaches to RA fatigue management.
authors.affiliation: Epidemiology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK k.druce@abdn.ac.uk.
authors.forename: Katie L
authors.initials: KL
authors.lastname: Druce
authors.affiliation: Epidemiology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Gareth T
authors.initials: GT
authors.lastname: Jones
authors.affiliation: Epidemiology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Macfarlane
authors.affiliation: Epidemiology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Neil
authors.initials: N
authors.lastname: Basu
mesh_terms: D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000188:drug therapy*; D005221:Fatigue / Q000188:drug therapy* / Q000209:etiology; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha
chemical_list: D000911:Antibodies, Monoclonal; D007155:Immunologic Factors; D014409:Tumor Necrosis Factor-alpha
keywords: anti-TNF; fatigue; rheumatoid arthritis