A comparison of six approaches for measuring utility values among patients with locally advanced cervical cancer.

ABSTRACT

BACKGROUND: Several instruments are available to measure health utility values. However, limited studies have not yet comprehensively assessed the agreement among these instruments. This study therefore aimed to investigate the performance and agreement of six instruments for utility measures: EQ-5D-3L, EQ-5D-5L (cTTO model), EQ-5D-5L (DCE model), EQ-5D-5L (Hybrid model), TTO, and VAS, among locally advanced cervical cancer (LACC) patients in Thailand. METHODS: We compared utility scores derived from six approaches using Friedman's test. We also assessed the agreement of utility scores between each pairwise comparison by intraclass correlation coefficient (ICC) and Bland-Altman plot. RESULTS: The mean (SD) utility values derived from six approaches were as follows 0.755 ± 0.248 (EQ-5D-3L), 0.801 ± 280 (TTO), 0.806 ± 0.156 (VAS), 0.871 ± 0.184 (cTTO model), 0.875 ± 0.168 (Hybrid model), and 0.900 ± 0.142 (DCE model). Significant differences across six approaches were found in Friedman's test. The ICC showed high agreement between EQ-5D-5L and EQ-5D-3L, and very high agreement between all three models of EQ-5D-5L. The Bland-Altman plots showed wide limit of agreement, except the pairwise comparison, between each model of the EQ-5D-5L. CONCLUSION: TTO, VAS, EQ-5D-3L and EQ-5D-5L could not be used interchangeably in LACC patients. The impact of using different instruments on economic evaluation findings warrants further investigation.