Thresholds for meaningful improvement in WOMAC scores need to be adjusted to patient characteristics after hip and knee replacement

David Kuklinski; Carlos J Marques; Karina Bohlen; Karl C Westphal; Frank Lampe; Alexander Geissler

doi:10.1016/j.jor.2022.01.002

Thresholds for meaningful improvement in WOMAC scores need to be adjusted to patient characteristics after hip and knee replacement

J Orthop. 2022 Jan 15:29:50-59. doi: 10.1016/j.jor.2022.01.002. eCollection 2022 Jan-Feb.

Authors

David Kuklinski¹, Carlos J Marques², Karina Bohlen³, Karl C Westphal⁴, Frank Lampe^{3

5}, Alexander Geissler⁶

Affiliations

¹ Technical University Berlin, Department of Health Care Management, Strasse des 17. Juni 135, 10623 Berlin, Germany.
² Science Office of the Orthopaedic and Joint Replacement Department, Schoen Clinic Hamburg Eilbek, Dehnhaide 120, 22081, Hamburg, Germany.
³ Orthopedic and Joint Replacement Department, Schoen Clinic Hamburg Eilbek, Dehnhaide 120, 22081, Hamburg, Germany.
⁴ Orthopedic and Joint Replacement Department, Schoen Clinic Neustadt, Am Kiebitzberg 10, 23730, Neustadt in Holstein, Germany.
⁵ Faculty of Life Sciences at the Hamburg University of Applied Sciences, Lohbrügger Kirchstraße 65, 21033, Hamburg, Germany.
⁶ School of Medicine, University of St. Gallen, St. Jakob-Strasse 21, 9000, St. Gallen, Switzerland.

Abstract

Purpose: To calculate unstratified and patient-specific meaningful improvement (MI) and patient acceptable symptom states (PASS) for the WOMAC total score in patients after total hip (THR) or total knee replacement (TKR).

Methods: A retrospective observational cohort study. Anchor-based receiver operator characteristics curves were used to estimate MI and PASS thresholds.

Results: Recovery paths were specific to individual characteristics of patients. An unstratified 12-months MI threshold of 28.1 (PASS: 13.3) and 17.8 (PASS: 15.8) for patients after THR and TKR, respectively, would unfairly detect critical recovery paths.

Conclusions: Thresholds for treatment success need to be as patient-specific as possible.

Keywords: Level of evidence: level III; MI, Meaningful Improvement; Meaningful improvement; PASS, Patient Acceptable Symptom State; PROMs, Patient-Reported Outcome Measures; Patient-reported outcomes; Prognostic study; THR, Total Hip Replacement; TKR, Total Knee Replacement; Total hip replacement; Total knee replacement; VBHC, Value-Based Health Care; Value-based health care; WOMAC; WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index.