OBJECTIVES: The availability of country-specific value sets for the EQ-5D-5L (5L) has implications for countries where cost-utility analysis is used for decision making. The aim of this study was to examine the implications of using the 3L and 5L scoring approaches for cost-utility analysis (CUA).

METHODS: Secondary data analysis of EMPARO-CU, an observational cohort study of patients treated for bladder or prostate cancer at 7 hospitals in Spain. The 3L and 5L were completed at baseline and at 6 and 12 months, and UK/English (base case), Dutch, and Spanish value sets applied. QALYs were derived from changes in utility scores among cancer patients stratified by progression status.

RESULTS: Of 739 patients, 430 had complete data at all time points (prostate n=275; bladder n=155). At baseline, UK 3L scores were substantially lower (mean [SD]: 0.82 [0.27]) than 5L (0.88 [0.18]). In absence of progression, mean absolute changes after 6 months were small (<0.03). Patients with progressive disease showed large declines in mean scores in prostate cancer (3L: -0.34 [0.15], 5L: -0.25 [0.11] and bladder cancer (3L: -0.16 [0.15], 5L: -0.09 [0.11]). The 3L generated larger QALY losses than the 5L for both cancer types using UK/English and Spanish but not the Dutch value sets.

CONCLUSIONS: Both the 3L and 5L captured large magnitudes of change when cancer progressed. For the UK and Spain, QALYs derived from 3L potentially translate into a larger QALY differential between treatments in a CUA, but generalizability beyond these cancers is unclear and inferences were limited by the small size of the progression subgroup. The relative merit of the 3L or 5L for QALY generation depended on baseline health status and value set.