A qualitative evaluation of the validity of published health utilities and generic health utility measures for capturing health-related quality of life (HRQL) impact of differentiated thyroid cancer (DTC) at different treatment phases

Purpose This study explored the impact of differentiated thyroid cancer (DTC) on health-related quality of life (HRQL) at different treatment phases and evaluated the validity of published DTC utilities and generic health utility measures (EQ-5D and SF-6D) for economic evaluation of treatments for radio-iodine (RAI) refractory DTC. Methods Focus groups and interviews were conducted with DTC patients grouped by treatment phase. Qualitative thematic analysis was conducted on interview/focus group transcripts. A thematic coding framework was developed to compare experiences between treatment phases and inform development of a conceptual model. Model concepts were mapped to EQ-5D and SF-6D domains/items. Results Eight focus groups and 11 individual interviews were conducted with 52 DTC patients. Fifty symptoms and HRQL concepts were identified. The impact of DTC and DTC treatment on emotional and cognitive functioning was reported across the treatment phases. The impact on daily activities, mobility, and energy levels was greatest for patients with recurring/persistent or RAI-refractory DTC. Of the 50 concepts, 25 and 27 mapped directly onto domains/items in the EQ-5D and SF-6D, respectively. The SF-6D covered a broader range of DTC impact on emotional/physical problems and daily/social activities than did the EQ-5D. Conclusions The conceptual model summarizes the wideranging impact of DTC and its treatment on patients' HRQL, particularly for those with recurring/persistent or RAI-refractory DTC. Findings suggest that published DTC utilities lack validity for RAI-refractory DTC and that the SF-6D may be more sensitive to HRQL impact of DTC than the EQ-5D.