Mapping Oswestry Disability Index Responses to EQ-5D-3L Utility Values: Are Cost-Utility Results Valid?

Ângela Jornada Ben*, Sylvia Pellekooren, Judith E. Bosmans, Raymond W. J. G. Ostelo, Esther T. Maas, Mohamed el Alili, Maurits W. van Tulder, Frank J. P. M. Huygen, Teddy Oosterhuis, Adri T. Apeldoorn, Miranda L. van Hooff, Johanna M. van Dongen

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Objectives: To develop and validate approaches for mapping Oswestry Disability Index responses to 3-level version of EQ-5D utility values and to evaluate the impact of using mapped utility values on cost-utility results compared with published regression models. Methods: Three response mapping approaches were developed in a random sample of 70% of 18 692 patients with low back pain: nonparametric approach (Non-p), nonparametric approach excluding logical inconsistencies (Non-peLI), and ordinal logistic regression (OLR). Performance was assessed in the remaining 30% using R-square (R2), root mean square error (RMSE), and mean absolute error (MAE). To evaluate whether MAEs and their 95% limits of agreement (LA) were clinically relevant, a minimally clinically important difference of 0.074 was used. Probabilities of cost-effectiveness estimated using observed and mapped utility values were compared in 2 economic evaluations. Results: The Non-p performed the best (R2 = 0.43; RMSE = 0.22; MAE = 0.03; 95% LA = −0.40 to 0.47) compared with the Non-peLI (R2 = 0.07; RMSE = 0.29; MAE = −0.15; 95% LA = −0.63 to 0.34) and OLR (R2 = 0.22; RMSE = 0.26; MAE = 0.02; 95% LA = −0.49 to 0.53). MAEs were lower than the minimally clinically important difference for the Non-p and OLR but not for the Non-peLI. Differences in probabilities of cost-effectiveness ranged from 1% to 4% (Non-p), 0.1% to 9% (Non-peLI), and 0.1% to 20% (OLR). Conclusions: Results suggest that the developed response mapping approaches are not valid for estimating individual patients’ 3-level version of EQ-5D utility values, and—depending on the approach—may considerably affect cost-utility results. The developed approaches did not perform better than previously published regression-based models and are therefore not recommended for use in economic evaluations.
Original languageEnglish
JournalValue in Health
Early online date2023
Publication statusE-pub ahead of print - 2023

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