Abstract
Purpose
Comparability of patient-reported outcome measures over different languages is essential to allow cross-national research. We investigate the comparability of the PROMIS Profile 29, a generic health-related quality of life measure, in general population samples in the UK, France, and Germany and present general population reference values.
Methods
A web-based survey was simultaneously conducted in the UK (n = 1509), France (1501), and Germany (1502). Along with the PROMIS Profile 29, we collected sociodemographic information as well as the EQ-5D. We tested measurement invariance by means of multigroup confirmatory factor analysis (CFA). Differences in the health-related quality of life between countries were modeled by linear regression analysis. We present general population reference data for the included PROMIS domains utilizing plausible value imputation and quantile regression.
Results
Multigroup CFA of the PROMIS Profile 29 showed that factor means are insensitive to potential measurement bias except in one item. We observed significant differences in patient-reported health between countries, which could be partially explained by the differences in overall ratings of health. The physical function and pain interference scales showed considerable floor effects in the normal population in all countries.
Conclusions
Scores derived from the PROMIS Profile 29 are largely comparable across the UK, France, and Germany. Due to the use of plausible value imputation, the presented general population reference values can be compared to data collected with other PROMIS short forms or computer-adaptive tests.
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Acknowledgements
This study was funded by the Centre Virchow-Villerme (https://virchowvillerme.eu/). We like to acknowledge the many people involved in development and translation of the PROMIS measures used in this study. Our thanks for their efforts to translate various PROMIS measures into German and French go in particular to Susan Bartlett, Marie-Eve Carrier, Erik Farin-Glattacker, Katja Heyduck, Sandra Nolte, and Inka Wahl. We thank Laurence Erdur and Nina Obbarius for their help in comparing the different language versions and Terrence Jorgensen for illuminating the pitfalls in measurement invariance testing of ordinal data. Furthermore, we would like to address special thanks to PROMIS translation manager Helena Correia.
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This study was funded by the Centre Virchow-Villerme.
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Fischer, F., Gibbons, C., Coste, J. et al. Measurement invariance and general population reference values of the PROMIS Profile 29 in the UK, France, and Germany. Qual Life Res 27, 999–1014 (2018). https://doi.org/10.1007/s11136-018-1785-8
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DOI: https://doi.org/10.1007/s11136-018-1785-8