Objectives: The aim of the study was to develop and compare utility value sets for the EORTC QLU-C10D, a cancer-specific utility instrument based on the EORTC QLQ-C30, using the preferences of the general public and cancer patients in Singapore, and to assess their measurement properties.
Methods: A total of 600 individuals from the general public were recruited using a multi-stage random sampling, along with 626 cancer patients with clinically confirmed diagnoses from outpatient clinics of the largest tertiary cancer hospital. Each participant valued 16 pairs of EORTC QLU-C10D health states using a discrete choice experiment (DCE). Conditional logit models were used to analyze the DCE responses of the general public and cancer patients separately. Utility values were assessed for known-group validity and responsiveness in the cancer patients by comparing mean values across subgroups of patients and calculating standardized response means using longitudinal EORTC QLQ-C30 data, respectively.
Results: Physical functioning and pain had the most impact on utility for both cancer patients and general public groups. Worst health state utility values were -0.821 and -0.463 for the general public and cancer patients, respectively. Cancer patients' values were lower for mild-to-moderate health states but higher for moderately-to-highly impaired states compared with the general public's values. Both value sets discriminated between patients with differing characteristics and responded equally well to improved health status, but the cancer patients' value set was slightly more responsive to deteriorated health.
Conclusions: EORTC QLU-C10D value sets based on the preferences of the Singaporean general public and cancer patients exhibited differences in values but similar psychometric properties.
© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.