title: Comparative responsiveness of outcome measures for total knee arthroplasty.
abstract: OBJECTIVE
  The aim of this study was to compare the responsiveness of various patient-reported outcome measures (PROMs) and clinician-reported outcomes following total knee arthroplasty (TKA) over a 2-year period.
  
  
  METHODS
  Data were collected in a prospective cohort study of primary TKA. Patients who had completed Forgotten Joint Score-12 (FJS-12), Western Ontario and McMaster Universities (WOMAC) osteoarthritis (OA) index, EQ-5D, Knee Society Score and range of movement (ROM) assessment were included. Five time points were assessed: pre-operative, 2 months, 6 months, 1 year and 2 years post-operative.
  
  
  RESULTS
  Data from 98 TKAs were available for analysis. Largest effect sizes (ES) for change from pre-operative to 2-month follow-up were observed for the Knee Society Score (KSS) Knee score (1.70) and WOMAC Total (-1.50). For the period from 6 months to 1 year the largest ES for change were shown by the FJS-12 (0.99) and the KSS Function Score (0.88). The EQ-5D showed the strongest ceiling effect at 1-year follow-up with 84.4% of patients scoring the maximum score. ES for the time from 1- to 2-year follow-up were largest for the FJS-12 (0.50). All other outcome measures showed ES equal or below 0.30.
  
  
  CONCLUSIONS
  Outcome measures differ considerably in responsiveness, especially beyond one year post-operatively. Joint-specific outcome measures are more responsive than clinician-reported or generic health outcome tools. The FJS-12 was the most responsive of the tools assessed; suggesting that joint awareness may be a more discerning measure of patient outcome than traditional PROMs.
authors.affiliation: Department of Orthopaedic Surgery, Kantonsspital St. Gallen, Rorschacherstrasse 95, CH-9000 St. Gallen, Switzerland. Electronic address: karlmeinrad.giesinger@kssg.ch.
authors.forename: K
authors.initials: K
authors.lastname: Giesinger
authors.affiliation: Department of Orthopaedic Surgery, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SA, UK. Electronic address: d.f.hamilton@ed.ac.uk.
authors.forename: D F
authors.initials: DF
authors.lastname: Hamilton
authors.affiliation: Department of Orthopaedic Surgery, Kantonsspital St. Gallen, Rorschacherstrasse 95, CH-9000 St. Gallen, Switzerland. Electronic address: bernhard.jost@kssg.ch.
authors.forename: B
authors.initials: B
authors.lastname: Jost
authors.affiliation: Department of Psychiatry and Psychotherapy, Innsbruck Medical University, Anichstr. 35, A-6020 Innsbruck, Austria. Electronic address: bernhard.holzner@uki.at.
authors.forename: B
authors.initials: B
authors.lastname: Holzner
authors.affiliation: Department of Psychosocial Research and Epidemiology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands. Electronic address: johannes.giesinger@i-med.ac.at.
authors.forename: J M
authors.initials: JM
authors.lastname: Giesinger
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000534:rehabilitation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods*; D017060:Patient Satisfaction; D011446:Prospective Studies; D016059:Range of Motion, Articular; D020127:Recovery of Function; D012720:Severity of Illness Index; D016896:Treatment Outcome
keywords: Forgotten joint score; Knee arthroplasty; Patient-reported outcome; Responsiveness; WOMAC score