Developing a Chinese value set for the FACT-8D, a cancer-specific multi-attribute utility instrument based on the FACT-general (FACT-G) questionnaire

This study aimed to develop a Chinese value set for the Functional Assessment of Cancer Therapy-8 Dimensions (FACT-8D), a cancer-specific preference-based utility instrument derived from the Functional Assessment of Cancer Therapy-General (FACT-G), to support the generation of QALY-based evidence for cost-utility analyses in oncology decision-making in China.

An online discrete choice experiment (DCE) was conducted among a nationally representative sample of the Chinese general population, recruited through quota sampling based on age, gender and residence. Each respondent completed 16 choice sets, with each set comprising two hypothetical health states defined by the eight FACT-8D dimensions, along with an associated survival duration. Conditional logistic regression was used to model preferences, parameterized within the quality-adjusted life year (QALY) framework. Post-stratification weights were applied to adjust for sampling non-representativeness. Utility decrements were derived from the estimated trade-offs between health problems and survival time.

The analysis included data from 2785 respondents who successfully completed the online survey. The largest utility decrements were associated with severe problems related to Pain, Nausea, and Sleep. In contrast, dimensions such as Social support, Work problems, and Worry were associated with comparatively smaller decrements. The worst possible health state was valued at - 0.153, indicating a state considered worse than being dead.

This study developed the first Chinese value set for the FACT-8D, reflecting societal preferences for cancer-related health outcomes. The value set enables the use of FACT-8D in cost-utility analyses of oncology interventions in China.