Patient acceptable symptom states after totalhip or knee replacement at mid-term follow-up: Thresholds of the Oxford hip and knee scores

J C Keurentjes; F R Van Tol; M Fiocco; C So-Osman; R Onstenk; A W M M Koopman-Van Gemert; R G Pöll; R G H H Nelissen

doi:10.1302/2046-3758.31.2000141

Patient acceptable symptom states after totalhip or knee replacement at mid-term follow-up: Thresholds of the Oxford hip and knee scores

Bone Joint Res. 2014 Jan 13;3(1):7-13. doi: 10.1302/2046-3758.31.2000141. Print 2014.

Authors

J C Keurentjes¹, F R Van Tol, M Fiocco, C So-Osman, R Onstenk, A W M M Koopman-Van Gemert, R G Pöll, R G H H Nelissen

Affiliation

¹ 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.

Abstract

Objectives: 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.

Keywords: Health-related quality of life; PROMs; Patient Acceptable Symptom State; Patient reported outcome measures; THR; TKR; Total hip replacement; Total knee replacement.

Grants and funding

Ongoing research grant of the Dutch Arthritis Association to Professor R. G. H. H Nelissen, Department of Orthopaedic Surgery, Leiden University Medical Center: grant number LLP-013 (http://www.reumafonds.nl/informatie-voor-doelgroepen/professionals/ongoing-research). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.