title: An evaluation of a patient-reported outcomes found computerized adaptive testing was efficient in assessing osteoarthritis impact.
abstract: OBJECTIVE
  Evaluate a patient-reported outcomes questionnaire that uses computerized adaptive testing (CAT) to measure the impact of osteoarthritis (OA) on functioning and well-being.
  
  
  METHODS
  OA patients completed 37 questions about the impact of OA on physical, social and role functioning, emotional well-being, and vitality. Questionnaire responses were calibrated and scored using item response theory, and two scores were estimated: a Total-OA score based on patients' responses to all 37 questions, and a simulated CAT-OA score where the computer selected and scored the five most informative questions for each patient. Agreement between Total-OA and CAT-OA scores was assessed using correlations. Discriminant validity of Total-OA and CAT-OA scores was assessed with analysis of variance. Criterion measures included OA pain and severity, patient global assessment, and missed work days.
  
  
  RESULTS
  Simulated CAT-OA and Total-OA scores correlated highly (r = 0.96). Both Total-OA and simulated CAT-OA scores discriminated significantly between patients differing on the criterion measures. F-statistics across criterion measures ranged from 39.0 (P < .001) to 225.1 (P < .001) for the Total-OA score, and from 40.5 (P < .001) to 221.5 (P < .001) for the simulated CAT-OA score.
  
  
  CONCLUSIONS
  CAT methods produce valid and precise estimates of the impact of OA on functioning and well-being with significant reduction in response burden.
authors.affiliation: QualityMetric Incorporated, 640 George Washington Highway, Lincoln, RI 02865, USA. mkosinski@qualitymetric.com
authors.forename: Mark
authors.initials: M
authors.lastname: Kosinski
authors.forename: Jakob B
authors.initials: JB
authors.lastname: Bjorner
authors.forename: John E
authors.initials: JE
authors.lastname: Ware
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Sullivan
authors.forename: Walter L
authors.initials: WL
authors.lastname: Straus
mesh_terms: D000223:Adaptation, Psychological; D004185:Disability Evaluation; D006801:Humans; D010003:Osteoarthritis / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy; D011788:Quality of Life; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014584:User-Computer Interface