title: Case finding for population-based studies of rheumatoid arthritis: comparison of patient self-reported ACR criteria-based algorithms to physician-implicit review for diagnosis of rheumatoid arthritis.
abstract: OBJECTIVE
  To evaluate the interrater reliability of rheumatologist diagnosis of rheumatoid arthritis (RA) and the concordance between rheumatologist and computer algorithms for assessing the accuracy of a diagnosis of RA.
  
  
  METHODS
  Self-reported data regarding symptoms and signs for a diagnosis of RA were considered by a panel of rheumatologists and by computer algorithms to assess the probability of a diagnosis of RA for 90 patients. The rheumatologists' review was validated through medical record.
  
  
  RESULTS
  The interrater reliability among rheumatologists regarding a diagnosis of RA was 84%; the chance-corrected agreement (kappa) was 0.66. Agreement between the rheumatologists' rating and the best-performing algorithm was 95%. Using rheumatologist's review as a standard, the sensitivity of the algorithm was 100%, specificity was 88%, and the positive predictive value was 91%. The validation of rheumatologist's review by medical record showed 81% sensitivity, 60% specificity, and 78% positive predictive value.
  
  
  CONCLUSIONS
  Reliability of rheumatologists' assignment of a diagnosis of RA by using self-report data is good. Algorithms defining symptoms as either joint swelling or tenderness with symptom duration >or=4 weeks have a better agreement with rheumatologist's diagnosis than do ones relying on a longer symptom duration.
  
  
  CONCLUSIONS
  These findings have important implications for health services research and quality improvement interventions pertinent to case finding for RA through self-report data.
authors.affiliation: UCLA Department of Medicine, Los Angeles, CA 90095-1736, USA. hhliu@ucla.edu
authors.forename: Honghu
authors.initials: H
authors.lastname: Liu
authors.forename: Judith O
authors.initials: JO
authors.lastname: Harker
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Wong
authors.forename: Catherine H
authors.initials: CH
authors.lastname: Maclean
authors.forename: Ken J
authors.initials: KJ
authors.lastname: Bulpitt
authors.forename: Brian S
authors.initials: BS
authors.lastname: Mittman
authors.forename: John
authors.initials: J
authors.lastname: Fitzgerald
authors.forename: Jennifer
authors.initials: J
authors.lastname: Grossman
authors.forename: Laurence Z
authors.initials: LZ
authors.lastname: Rubenstein
authors.forename: Bevra
authors.initials: B
authors.lastname: Hahn
authors.forename: Harold E
authors.initials: HE
authors.lastname: Paulus
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Kahn
mesh_terms: D000465:Algorithms; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000453:epidemiology*; D003936:Diagnosis, Computer-Assisted; D006801:Humans; D008487:Medical History Taking; D008499:Medical Records; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity