title: Patient acceptable symptom states after totalhip or knee replacement at mid-term follow-up: Thresholds of the Oxford hip and knee scores.
abstract: OBJECTIVE
  To define Patient Acceptable Symptom State (PASS) thresholds for the Oxford hip score (OHS) and Oxford knee score (OKS) at mid-term follow-up.
  
  
  METHODS
  In a prospective multicentre cohort study, OHS and OKS were collected at a mean follow-up of three years (1.5 to 6.0), combined with a numeric rating scale (NRS) for satisfaction and an external validation question assessing the patient's willingness to undergo surgery again. A total of 550 patients underwent total hip replacement (THR) and 367 underwent total knee replacement (TKR).
  
  
  RESULTS
  Receiver operating characteristic (ROC) curves identified a PASS threshold of 42 for the OHS after THR and 37 for the OKS after TKR. THR patients with an OHS ≥ 42 and TKR patients with an OKS ≥ 37 had a higher NRS for satisfaction and a greater likelihood of being willing to undergo surgery again.
  
  
  CONCLUSIONS
  PASS thresholds appear larger at mid-term follow-up than at six months after surgery. With- out external validation, we would advise against using these PASS thresholds as absolute thresholds in defining whether or not a patient has attained an acceptable symptom state after THR or TKR. Cite this article: Bone Joint Res 2014;3:7-13.
authors.affiliation: Leiden University Medical Center, Departmentof Orthopaedic Surgery/Department of Medical Statistics, Albinusdreef2, Room J-09-127, PO Box9600, Postzone J-11-S, 2300RC Leiden, the Netherlands.
authors.forename: J C
authors.initials: JC
authors.lastname: Keurentjes
authors.forename: F R
authors.initials: FR
authors.lastname: Van Tol
authors.forename: M
authors.initials: M
authors.lastname: Fiocco
authors.forename: C
authors.initials: C
authors.lastname: So-Osman
authors.forename: R
authors.initials: R
authors.lastname: Onstenk
authors.forename: A W M M
authors.initials: AW
authors.lastname: Koopman-Van Gemert
authors.forename: R G
authors.initials: RG
authors.lastname: Pöll
authors.forename: R G H H
authors.initials: RG
authors.lastname: Nelissen
keywords: Health-related quality of life; PROMs; Patient Acceptable Symptom State; Patient reported outcome measures; THR; TKR; Total hip replacement; Total knee replacement