Health state utility valuation in radioactive iodine-refractory differentiated thyroid cancer

Beth A Fordham,1 Cicely Kerr,1 Hayley M de Freitas,1 Andrew J Lloyd,1 Karissa Johnston,2 Corey L Pelletier,3 Gabriel Tremblay,3 Anna Forsythe,3 Bryan McIver,4 Ezra EW Cohen5 1ICON Patient Reported Outcomes, Oxford, UK; 2ICON Epidemiology, Toronto, ON, Canada; 3Eisai Inc., NJ, 4Moffitt Cancer Center, FL, 5University of California San Diego Moores Cancer Center, La Jolla, CA, USA Purpose: The aim of this study was to elicit utilities for radioactive iodine-refractory differentiated thyroid cancer (RR-DTC) and evaluate the impact of treatment response and toxicities on quality of life.Patients and methods: RR-DTC health states were developed based on data from a previous qualitative study and iterative review by clinical experts. Following piloting, health states underwent valuation by 100 members of the UK public during time trade-off interviews. Mean utilities and descriptive distribution statistics were calculated, and a logistic regression analysis was conducted.Results: The demographic characteristics of the study sample were generally reflective of the UK population. Clear differentiation in valuation between health states was observed. No response/stable disease had an adjusted utility value of 0.87, with a corresponding gain of +0.04 following a treatment response and a decline of –0.35 for disease progression. Adverse events were associated with utility decrements between –0.47 (grade III diarrhea) and –0.05 (grade I/II alopecia).Conclusion: The trade-off interviews derived utility weights show clear differentiation between RR-DTC health states in response to treatment. The values reported in this study are suitable for cost-effectiveness evaluations for new treatments in RR-DTC. Keywords: differentiated thyroid cancer, radioactive iodine-refractory, health-related quality of life, health utility, vignette