Health state utilities for metastatic breast cancer in Taiwan

New developments in medications for metastatic breast cancer (MBC) can be of great benefit to patients, but unfortunately these medicines also increase expenditures. Cost-utility analyses (CUAs) are needed to allocate health resources properly, and health utility values are required to calculate quality-adjusted life years in those CUAs.

The aims of this study were to measure health utility values for several MBC-related health states and certain breast cancer treatment-related grade 3/4 adverse drug reactions (ADRs). In addition, we examined whether different methods and respondents' characteristics would influence the utility values elicited.

A cross-sectional survey was conducted. The visual analogue scale (VAS) and time trade-off (TTO) methods were used to measure health utilities. Four MBC and nine ADR health states were selected for evaluation based on literature review and expert opinion. Information about respondents' demographic and clinical characteristics were collected to examine the relationship between utilities and participant characteristics.

A total of 102 patients participated in this study. The TTO-elicited values were higher than the VAS-derived scores except for two MBC-related health states. Among the MBC health states assessed, the TTO preference score ranged from 0.04 (palliative MBC) to 0.62 (responding MBC). For grade 3/4 ADRs, the mean TTO-derived utility values ranged from 0.35 (nausea/vomiting) to 0.79 (fatigue). The ranking of the preference scores derived from the VAS was similar to that of the TTO-elicited scores.

This study obtained health state utility values for MBC and grade 3/4 ADRs using both the TTO and the VAS, which provides useful data for future CUAs.