Mapping analysis to predict the associated EuroQol five-dimension three-level utility values from the Oxford Knee Score: a prediction and validation study. (1st July 2022)

• Record Type: Journal Article
• Authors: Clement, Nick D.; Afzal, Irrum; Peacock, Christian J. H.; MacDonald, Deborah; Macpherson, Gavin J.; Patton, James T.; Asopa, Vipin; Sochart, David H.; Kader, Deiary F.
• Is Part Of: Bone & joint open. Volume 3:Number 7(2022)
• Page Start: 573
• Page End: 581
• Publication Date: 2022-07-01
• Subjects: EQ-5D -- Oxford Knee Score -- Arthroplasty -- Outcome -- Predictors -- EQ-5D-3L -- total knee arthroplasty (TKA) -- linear regression analysis -- BMI -- patient-reported outcome measure (PROM) -- Spearman correlations -- Pearson correlation -- t-test; Orthopedic surgery -- Periodicals; Musculoskeletal system -- Surgery -- Periodicals; 617.47
• DOI: 10.1302/2633-1462.37.BJO-2022-0054.R1
• Languages: English
• ISSNs: 2633-1462

Abstract

Abstract : Aims: The aims of this study were to assess mapping models to predict the three-level version of EuroQoL five-dimension utility index (EQ-5D-3L) from the Oxford Knee Score (OKS) and validate these before and after total knee arthroplasty (TKA). Methods: A retrospective cohort of 5, 857 patients was used to create the prediction models, and a second cohort of 721 patients from a different centre was used to validate the models, all of whom underwent TKA. Patient characteristics, BMI, OKS, and EQ-5D-3L were collected preoperatively and one year postoperatively. Generalized linear regression was used to formulate the prediction models. Results: There were significant correlations between the OKS and EQ-5D-3L preoperatively ( r = 0.68; p < 0.001) and postoperatively ( r = 0.77; p < 0.001) and for the change in the scores ( r = 0.61; p < 0.001). Three different models (preoperative, postoperative, and change) were created. There were no significant differences between the actual and predicted mean EQ-5D-3L utilities at any timepoint or for change in the scores (p > 0.090) in the validation cohort. There was a significant correlation between the actual and predicted EQ-5D-3L utilities preoperatively ( r = 0.63; p < 0.001) and postoperatively ( r = 0.77; p < 0.001) and for the change in the scores ( r = 0.56; p < 0.001). Bland-Altman plots demonstrated that a lower utility was overestimated, and higher utility was underestimated. The individual predicted EQ-5D-3L that was within ± 0.05 and ± 0.010 (minimal clinically important difference (MCID)) of the actual EQ-5D-3L varied between 13% to 35% and 26% to 64%, respectively, according to timepoint assessed and change in the scores, but was not significantly different between the modelling and validation cohorts (p ≥ 0.148). Conclusion: The OKS can be used to estimate EQ-5D-3L. Predicted individual patient utility error beyond the MCID varied from one-third to two-thirds depending on timepoint assessed, but the mean for a cohort did not differ and could be employed for this purpose. Cite this article: Bone Jt Open 2022;3(7):573–581.