Mapping the QLQ-C30 quality of life cancer questionnaire to EQ-5D patient preferences.

Background: Although cancer-specific Health-Related Quality of Life (HRQOL) are commonly included in randomized clinical trials or other prospective non-randomized clinical studies, it is rare that preference-based instruments are used that allow the calculation of a utility weight suitable for estimating quality-adjusted life-years gained.

Objective: To develop a mapping algorithm to transform the EORTC QLQ-C30 questionnaire responses into EQ-5D derived utilities.

Study Design: Retrospective data analysis of a multicentre, multicountry prospective clinical trial in breast cancer patients.

Methods: Regression analysis of individual pairs of EQ-5D and QLQ-C30 scores.

Results: A model that explained 80% of the variance was developed to estimate EQ-5D Utilities from QLQ-C30 scores at individual level. From this reliable group level means and deviations can be derived.

Conclusions: Mapping from QLQ-C30 scores to EQ-5D-derived utilities when only QLQ-C30 data are available has been shown to be possible with good accuracy. Validation of the proposed algorithm in other external clinical datasets should be encouraged.