Mapping analyses to estimate EQ-5D utilities and responses based on Oxford Knee Score
This webpage gives supporting material for the following paper:
Dakin, H, Gray, A, Murray, D. (2013) Mapping analyses to estimate EQ-5D utilities and responses based on Oxford Knee Score. Quality of Life Research, 22(3):683-94.
The following supplementary files are available:
• Stata command to translate OKS responses for individual patients into EQ-5D utilities using a variety of different national tariffs: This ado file, oks2eq, has been published by the Stata Journal (st0305, Ramos-Goñi 2013) and is available through Stata (type net describe st0305) and via the Stata website (www.stata-journal.com/article.html?article=st0305).
• Excel spreadsheet to translate OKS into EQ-5D using primary or secondary data : This Excel file is hosted on the HERC website and offers two different mapping models depending on the type of data available. Where responses to each question on the OKS are available for a cohort of individual patients, the spreadsheet uses the published multinomial logistic regression model to estimate mean predicted EQ-5D utility using the UK time-trade-off tariff. However, in some situations (e.g. health economic models), only secondary data on mean OKS are available. We have therefore developed a simplified version of the mapping algorithm that directly predicts EQ-5D utility based on total OKS. Although this is less accurate than the published response mapping algorithm, the linear model and low data requirement mean that it can be used on secondary data when individual patient data are not available. This should be cited as: Dakin, H, Gray, A, and Murray, D (2013). Mapping analyses to estimate EQ-5D utilities and responses based on Oxford Knee Score. Qual Life Res, 22(3):683-94. Spreadsheet algorithm for predicting EQ-5D utilities. Available from http://www.herc.ox.ac.uk/downloads/mappingOKS.
• Variance-covariance matrix for the multinomial logistic regression : This Excel 2007 file (available from the journal website http://link.springer.com/article/10.1007%2Fs11136-012-0189-4) provides the data needed to propagate uncertainty around the mean predicted utility into subsequent analyses. Please cite this matrix as: Dakin, H, Gray, A, and Murray, D (2013). Mapping analyses to estimate EQ-5D utilities and responses based on Oxford Knee Score. Qual Life Res, 22(3):683-94.
Disclaimer While the authors have made every effort to ensure the reliability of this algorithm, they will not accept responsibility for any errors, omissions, inaccuracies or any consequences arising from the use of the algorithm. Users do so at their own risk.