title: Minimal clinically important improvement (MCII) and patient-acceptable symptom state (PASS) in total hip arthroplasty (THA) patients 1 year postoperatively.
abstract: OBJECTIVE
  The increased use of patient-reported outcomes (PROs) in orthopedics requires data on estimated minimal clinically important improvements (MCIIs) and patient-acceptable symptom states (PASSs). We wanted to find cut-points corresponding to minimal clinically important PRO change score and the acceptable postoperative PRO score, by estimating MCII and PASS 1 year after total hip arthroplasty (THA) for the Hip Dysfunction and Osteoarthritis Outcome Score (HOOS) and the EQ-5D.
  
  
  METHODS
  THA patients from 16 different departments received 2 PROs and additional questions preoperatively and 1 year postoperatively. The PROs included were the HOOS subscales pain (HOOS Pain), physical function short form (HOOS-PS), and hip-related quality of life (HOOS QoL), and the EQ-5D. MCII and PASS were estimated using multiple anchor-based approaches.
  
  
  RESULTS
  Of 1,837 patients available, 1,335 answered the preoperative PROs, and 1,288 of them answered the 1-year follow-up. The MCIIs and PASSs were estimated to be: 24 and 91 (HOOS Pain), 23 and 88 (HOOS-PS), 17 and 83 (HOOS QoL), 0.31 and 0.92 (EQ-5D Index), and 23 and 85 (EQ-VAS), respectively. MCIIs corresponded to a 38-55% improvement from mean baseline PRO score and PASSs corresponded to absolute follow-up scores of 57-91% of the maximum score in THA patients 1 year after surgery.
  
  
  CONCLUSIONS
  This study improves the interpretability of PRO scores. The different estimation approaches presented may serve as a guide for future MCII and PASS estimations in other contexts. The cutoff points may serve as reference values in registry settings.
authors.affiliation: Department of Orthopaedic Surgery and Traumatology , Odense University Hospital, Institute of Clinical Research , University of Southern Denmark.
authors.forename: Aksel
authors.initials: A
authors.lastname: Paulsen
authors.forename: Ewa M
authors.initials: EM
authors.lastname: Roos
authors.forename: Alma B
authors.initials: AB
authors.lastname: Pedersen
authors.forename: Søren
authors.initials: S
authors.lastname: Overgaard
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000523:psychology / Q000534:rehabilitation*; D015331:Cohort Studies; D003718:Denmark; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery; D010147:Pain Measurement / Q000379:methods; D017060:Patient Satisfaction; D011594:Psychometrics; D011788:Quality of Life; D020127:Recovery of Function; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055815:Young Adult