Comparison of EQ-5D-3L with QLU-C10D in Metastatic Melanoma Using Cost-Utility Analysis

BACKGROUND: The National Institute for Health and Care Excellence (NICE) prefers the use of the generic EQ-5D instrument to estimate quality-adjusted life years (QALYs), and recommends that condition-specific instruments only be used when EQ-5D data are not available or not appropriate. OBJECTIVE: This study aimed to compare the utility gain and cost-effectiveness results of using the generic EQ-5D-3L instrument to the condition-specific Quality-of-Life Utility Measure-Core 10 dimensions (QLU-C10D) by applying both sets of values in a published cost-utility analysis (CUA) of immunotherapy for metastatic melanoma. METHODS: Quality-of-life data were drawn from a clinical study in which both QLQ-C30 and EQ-5D-3L tools were used. The potential influence of the two instruments on cost-effectiveness was assessed using a three-state Markov model. Descriptive statistics and standard health economic outputs were compared between analyses that applied the two different utility measures. RESULTS: Mean baseline utility values as measured by the QLU-C10D (mean = 0.744, SD = 0.219) were not statistically different (p > 0.05) compared to values derived from EQ-5D-3L (mean = 0.735, SD = 0.239). The two instruments were correlated (Pearson's correlation = 0.74); however, concordance was low (Lin's concordance correlation coefficient < 0.90) at baseline. The model predicted slightly higher QALYs gained when using EQ-5D-3L over QLU-C10D-derived utilities (1.87 vs 1.74, respectively). This resulted in an incremental cost-effectiveness ratio of US$30.5K when using EQ-5D-3L utilities, compared to US$32.7K when using QLU-C10D utilities. Cost-effectiveness acceptability curves based on the two sets of utilities were almost indistinguishable. CONCLUSION: This study supports the use of the generic EQ-5D instrument in immunotherapy treated metastatic melanoma, and found no additional benefit for using the disease-specific QLU-C10D when using Australian weights.