OBJECTIVES

: The existence of important dissimilarities between EQ-5D-3L and EQ-5D-5L is a key topic in current research. This study compares the performance of the 3L and 5L in capturing changes in quality-of-life and the resulting impact on estimates of QALYs.

METHODS

: Cancer 2015 enrols newly diagnosed, treatment-naïve cancer patients, who complete quality-of-life questionnaires at baseline, and at various follow-up points. For the first four years the EQ-5D-3L was used. From late 2015, data collection moved from the 3L to the 5L, for newly enrolled participants and also for those undergoing follow-up. EORTC QLQ-C30 outcomes for all respondents at baseline and each follow-up point are also collected. Genetic Matching techniques are used to construct a match comparison group of patients. For matched QLQ-C30 profiles, we compare 3L and 5L tariffs, as well as the magnitude of changes in quality-of-life at different points along the treatment trajectory. We quantify the impact of the 5L versus the 3L on the overall QALYs gained by patients over a defined treatment period.

RESULTS

: A total of 2,286 patients completed either the 3L or the 5L at baseline, 1,797 respondents completed follow-ups; average follow-up of 719 days. At baseline 29% of those patients who completed the 3L were in full health (11111), compared to 23% of those patients which completed the 5L. 88 of the 243 3L profiles were used at baseline compared with 109 of the 3,125 5L profiles. The average tariff at baseline for the 3L respondents was 0.751 compared with 0.851 for 5L respondents.

CONCLUSIONS

: This project offers a unique understanding of the sensitivity of the EQ-5D-3L and EQ-5D-5L in a cohort of cancer patients and it will provide much needed evidence on the relative merits of both measures, as well as the potential implications of the adoption of the 5L measure as a new reference.