title: Fibromyalgic rheumatoid arthritis and disease assessment.
abstract: OBJECTIVE
  We evaluated fibromyalgic RA to determine its clinical impact, identification using core clinical assessments and influence identifying active disease using disease activity scores (DAS-28).
  
  
  METHODS
  We examined the impact and identification using core clinical assessments (tender minus swollen joint counts) of fibromyalgic RA (> or =11 tender points) in initial (105 patients) and replicate (100 patients) cohorts. Receiver operator characteristic (ROC) curves optimized the cut-off points using tender minus swollen joint counts; their validity was confirmed in a routine practice cohort (321 patients). We evaluated whether fibromyalgic RA affected the identification of active disease using DAS-28 (> or =5.1) and the clinical disease activity index (CDAI).
  
  
  RESULTS
  A total of 18/105 and 12/100 patients in initial and replicate cohorts, respectively, had fibromyalgic RA. This was identified by > or =7 tender minus swollen joint counts with 83% sensitivity and 80% specificity in the initial cohort (72 and 98% in replicate, respectively) and ROC area under the curve 0.80 (0.94 in replicate). 'Fibromyalgic' RA (tender point scores in initial and tender minus swollen joints in clinical practice cohorts) had higher DAS-28, pain, fatigue and HAQ scores. More fibromyalgic RA patients had active disease by DAS-28 (odds ratio 14.3; 95% CI 5.5, 37.1; and CDAI 17.2; 95% CI 6.1, 48.5); conventional assessments (three or more tender joints; three or more swollen joints; ESR > or =28 mm/h) showed no difference (1.75; 95% CI 0.72, 4.3).
  
  
  CONCLUSIONS
  Fibromyalgic RA affects 12-17% of RA outpatients and results in worse functional outcomes. DAS-28 scores over-interpret active disease in fibromyalgic RA.
authors.affiliation: Department of Rheumatology, King's College London, School of Medicine at Guy's, King's College and St Thomas' Hospitals, Weston Education Centre, London, UK. louise.pollard@kcl.ac.uk
authors.forename: Louise C
authors.initials: LC
authors.lastname: Pollard
authors.forename: Gabrielle H
authors.initials: GH
authors.lastname: Kingsley
authors.forename: Ernest H
authors.initials: EH
authors.lastname: Choy
authors.forename: David L
authors.initials: DL
authors.lastname: Scott
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy / Q000503:physiopathology*; D015331:Cohort Studies; D005221:Fatigue / Q000188:drug therapy / Q000209:etiology*; D005260:Female; D005356:Fibromyalgia / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D007596:Joints; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy / Q000209:etiology*; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D018501:Antirheumatic Agents