title: Minimal clinically important differences of 3 patient-rated outcomes instruments.
abstract: OBJECTIVE
  Patient-rated instruments are increasingly used to measure orthopedic outcomes. However, the clinical relevance of modest score changes on such instruments is often unclear. This study was designed to define the minimal clinically important differences (MCIDs) of the Disabilities of the Arm, Shoulder, and Hand (DASH), QuickDASH (subset of DASH), and Patient-Rated Wrist Evaluation (PRWE) questionnaires for atraumatic conditions of the hand, wrist, and forearm.
  
  
  METHODS
  We prospectively analyzed 102 patients undergoing nonoperative treatment for isolated tendinitis, arthritis, or nerve compression syndromes from the forearm to the hand. By phone, patients completed the DASH, QuickDASH, and PRWE at enrollment and at 2 weeks (n = 78 used in the analysis) and 4 weeks (n = 24 used in the analysis) after initiating treatment. Patients reporting clinical improvement each contributed a single data point categorized as no change (n = 41), minimal improvement (n = 30), or marked improvement (n = 31) via a validated anchor-based approach. We calculated the MCID as the mean change score for each outcome measure in the minimal improvement group.
  
  
  RESULTS
  The MCID (95% confidence interval) for the DASH was 10 (5-15). The MCID for the QuickDASH was 14 (9-20). The MCID was 14 (8-20) for the PRWE. The MCID values were significantly different from changes in these outcome measures at times of either no change or marked improvement. The MCID values positively correlated with baseline outcome measure scores to a greater degree than final outcome measure scores.
  
  
  CONCLUSIONS
  Longitudinal changes on the DASH of 10 points, on the QuickDASH of 14 points, and on the PRWE of 14 points represent minimal clinically important changes. We recommend application of these MCID values for group-level analysis when conducting research and interpreting data examining groups of patients as opposed to assessing individual patients. These MCID values may provide a basis for sample size calculations for future investigation using these common patient-rated outcome measures.
  
  
  METHODS
  Diagnostic III.
authors.affiliation: Department of Orthopaedic Surgery, Washington University School of Medicine, St Louis, MO, USA.
authors.forename: Amelia A
authors.initials: AA
authors.lastname: Sorensen
authors.forename: Daniel
authors.initials: D
authors.lastname: Howard
authors.forename: Wen Hui
authors.initials: WH
authors.lastname: Tan
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Ketchersid
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Calfee
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D005542:Forearm / Q000503:physiopathology; D006225:Hand / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000175:diagnosis / Q000628:therapy*; D010003:Osteoarthritis / Q000175:diagnosis / Q000628:therapy*; D010147:Pain Measurement / Q000379:methods*; D010358:Patient Participation; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology*; D020127:Recovery of Function; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D052256:Tendinopathy / Q000175:diagnosis / Q000628:therapy*; D016896:Treatment Outcome