TY - JOUR

T1 - Categorization of changes in the Oxford Knee Score after Total Knee Replacement

T2 - An interpretive tool developed from a dataset of 46,094 replacements

AU - Mikkelsen, Mette

AU - Gao, Anqi

AU - Ingelsrud, Lina Holm

AU - Beard, David

AU - Troelsen, Anders

AU - Price, Andrew

N1 - Publisher Copyright: © 2020 Elsevier Inc. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/4/1

Y1 - 2021/4/1

N2 - OBJECTIVES: The objective of the study was to create an interpretive categorical classification for the transition in the Oxford Knee Score (OKS) change score (ΔOKS) using the anchor-based method.STUDY DESIGN AND SETTING: Registry data from 46,094 total knee replacements from the year 2014/15, were accessed via the Health and Social Care Information Center official website. Data included preoperative and 6-month follow-up OKS and response to the transition anchor question. Categories were determined using Gaussian approximation probability and k-fold cross-validation.RESULTS: Four categories were identified with the corresponding ΔOKS intervals: "1. much better" (≥16), "2. a little better" (7-15), "3. about the same" (1-6), and "4. much worse" (≤0) based on the anchor questions' original five categories. The mean 10-fold cross-validation error was 0.35 OKS points (95% confidence interval 0.12 to 0.63). Sensitivity ranged from 0.34 to 0.68; specificity ranged from 0.74 to 0.95.CONCLUSION: We have categorized the change score into a clinically meaningful classification. We argue it should be an addition to the continuous OKS outcome to contextualize the results in a way more applicable to the shared decision-making process and for interpreting research results.

AB - OBJECTIVES: The objective of the study was to create an interpretive categorical classification for the transition in the Oxford Knee Score (OKS) change score (ΔOKS) using the anchor-based method.STUDY DESIGN AND SETTING: Registry data from 46,094 total knee replacements from the year 2014/15, were accessed via the Health and Social Care Information Center official website. Data included preoperative and 6-month follow-up OKS and response to the transition anchor question. Categories were determined using Gaussian approximation probability and k-fold cross-validation.RESULTS: Four categories were identified with the corresponding ΔOKS intervals: "1. much better" (≥16), "2. a little better" (7-15), "3. about the same" (1-6), and "4. much worse" (≤0) based on the anchor questions' original five categories. The mean 10-fold cross-validation error was 0.35 OKS points (95% confidence interval 0.12 to 0.63). Sensitivity ranged from 0.34 to 0.68; specificity ranged from 0.74 to 0.95.CONCLUSION: We have categorized the change score into a clinically meaningful classification. We argue it should be an addition to the continuous OKS outcome to contextualize the results in a way more applicable to the shared decision-making process and for interpreting research results.

KW - Interpretive tool

KW - Knee replacement

KW - Oxford Knee Score

KW - Patient-reported outcome

UR - http://www.scopus.com/inward/record.url?scp=85098681953&partnerID=8YFLogxK

U2 - 10.1016/j.jclinepi.2020.12.007

DO - 10.1016/j.jclinepi.2020.12.007

M3 - Journal article

C2 - 33301905

VL - 132

SP - 18

EP - 25

JO - Journal of Clinical Epidemiology

JF - Journal of Clinical Epidemiology

SN - 0895-4356

ER -