title: Fibromyalgia in patients with rheumatoid arthritis: driven by depression or joint damage?
abstract: OBJECTIVE
  Studies have shown an increased incidence of fibromyalgia (FMS) in RA patients. The aims of this study were to explore the effect of mood and disease damage on the prevalence of FMS.
  
  
  METHODS
  RA patients underwent a standardised clinical assessment, including disease activity (DAS-28), disease damage (mechanical joint score, MJS), fibromyalgia tender point assessment and the Hospital Anxiety and Depression Scale (HADS) and Health Assessment Questionnaire (HAQ). Patients were classified with FMS using two criteria a) tender-swollen joint count was ≥7 or b) tender point score of ≥11/18.
  
  
  RESULTS
  44/285 (15%) patients were classified as having FMS using the joint count difference of ≥7, compared to 18/285 (6%) using the tender point score of >11. Using the joint count difference to classify patients as having FMS, those with FMS had higher HAQ scores than those without FMS (2.12 vs. 1.5, p<0.0001). Although the DAS-28 was higher in this group (5.4 vs. 3.82, p<0.0001), the MJS was similar (8 vs. 7, p=0.19), suggesting similar levels of joint damage. Those classified as having FMS were more likely to have HAD-D scores of >11 (25% vs. 6%, p=0.0001).
  
  
  CONCLUSIONS
  Coexistent FMS was common in our cohort, although using the tender point count to define FMS classified fewer patients with FMS. Within this group those with FMS had higher levels of depression but similar scores for joint damage indicating that in this cohort FMS and poorer physical functioning is mediated by low mood rather than joint damage.
authors.affiliation: Rheumatology Department, Haywood Hospital, Stoke on Trent, ST6 7AG, UK.
authors.forename: S R
authors.initials: SR
authors.lastname: Kapoor
authors.forename: S L
authors.initials: SL
authors.lastname: Hider
authors.forename: A
authors.initials: A
authors.lastname: Brownfield
authors.forename: D L
authors.initials: DL
authors.lastname: Mattey
authors.forename: J C
authors.initials: JC
authors.lastname: Packham
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D059350:Chronic Pain / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D015331:Cohort Studies; D015897:Comorbidity; D003863:Depression / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D005356:Fibromyalgia / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D006304:Health Status; D006801:Humans; D006930:Hyperalgesia / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D007596:Joints / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013577:Syndrome; D013585:Synovitis / Q000175:diagnosis / Q000503:physiopathology; D006113:United Kingdom / Q000453:epidemiology