In a study published in The Journal of Radiation Oncology, patient-elicited utilities to determine patient preferences between treatments were compared to clinically reported parameters and other patient-reported QOL parameters in patients with metastatic brain disease.2 Patients with 1-3 newly diagnosed brain metastases who were eligible for stereotactic radiosurgery and met inclusion/exclusion criteria were randomly assigned to either stereotactic radiosurgery and whole-brain radiation therapy or stereotactic radiosurgery alone.
A time trade off (TTO) utility elicitation instrument was used to determine the amount of time in perfect health for which patients would be willing to trade up to 1, 5, or 10 years of life in their current health state. Patients were asked to choose between living in a specified time horizon (1, 5, or 10 years) in their existing health state versus living for a variable amount of time in perfect health. These values were then compared to formal neurocognitive function (NCF) testing— including tests of memory function (Hopkins Verbal Learning Test–Revised [HVLT-R]) and executive function (Trail Making Test Part B), and other self-reported QOL (Functional Assessment of Cancer Therapy–Brain [FACT-BR]) and symptoms (MD Anderson Symptom Inventory–Brain Tumor [MDASI-BT])(sleep)—and also compared to a CRO (the Karnofsky performance status [KPS] score) at baseline and at predetermined intervals afterward throughout the study period. The 3 different TTO utility scores were evaluated by regression analysis (with the TTO scores as the dependent variable and the NCF, KPS, FACT-BR, and MDASIBT scores as independent variables) and demographic variables, clinical characteristics, treatment arms, and time collection periods as covariates.
The study enrolled 58 patients, of whom 55 had baseline data collection for TTO utility, NCF, KPS, and QOL scores. Patients who were willing to trade more time for better health were presumed to have a lower preference for their current health state and, therefore, a lower TTO utility score. The mean TTO utility scores at baseline were 0.88, 0.83, and 0.77 with the 1-year, 5-year, and 10-year time horizon, respectively, and at baseline 78%, 61%, and 50% of the patients at 1-year, 5-year, and 10-year time horizons were unwilling to trade any time at all for a better QOL. In the regression analyses, after adjusting for demographics, clinical factors, and time, significant associations were found between 10-year TTO utility and FACT-BR scores (P < .01) and 10-year TTO utility and MDASI-BT scores (P = .047) as well as between 5-year TTO utility and FACT-BR scores (P < .01) and 5-year TTO utility and MDASI-BT scores (P = .037). There were no associations between 1-year utility and any other variables or for the 10-year and 5-year for the KPS or NCF scores.