OBJECTIVES: Value assessments of new treatments for metastatic renal cell carcinoma (RCC) should include outcomes that are most important to patients. This study aimed to quantify and compare the conditional relative importance of the attributes of RCC treatments to patients and physicians in the United States.
METHODS: Patients with RCC and physicians who treat RCC completed an online discrete-choice experiment survey with a fractional factorial D-optimal experimental design. In a series of 12 questions, respondents chose between two hypothetical treatments defined in terms of six attributes: progression-free survival (PFS), probability of living ≥ 3 years (PL3Y), skin reactions, severity of fatigue, mode of administration, and monthly co-payment. Treatment choices were analyzed using a random-parameters logit model to estimate relative preference weights for the attribute levels and conditional relative attribute importance (i.e. the importance of an attribute relative to all other attributes conditional on the range of levels of that attribute).
RESULTS: Overall, 201 patients and 142 physicians completed the survey. For both patients and physicians, PL3Y was the attribute with the greatest and statistically significant conditional relative importance. Estimates of the conditional relative importance of PFS, skin reactions, and mode of administration for patients, and for PFS and mode of administration for physicians, were not statistically significant. The preferences for improvements in PFS were independent of the level of PL3Y for both patients and physicians. Conditional relative attribute importance varied by patient disease stage.
CONCLUSIONS: Patients and physicians indicated that PL3Y was the most important treatment attribute and was significantly more important than PFS. Importance rankings differed between physicians and patients and between all patients and those with advanced/metastatic disease.