Patient, care partner, and oncologist perspectives on clinically important survival thresholds after considering time toxicity in advanced cancer.

A treatment's time toxicity (measured using contact days) can decrease days spent at home (home days). We evaluated the minimum clinically important difference (MCID) and non-inferiority margin (NIM) of home days, and treatment acceptance when all additional survival time was spent in health care by surveying people with lived (patients, n = 42; informal care partners, n = 29) and professional (oncologists, n = 8) experience of advanced cancer. All 3 groups reported similar MCIDs and NIMs (6-month survival; median MCID range, 14-15; P = .79; median NIM range, 5-11; P = .14). Care partners (48%) and patients (21%) more often accepted 2-week survival gains without an increase in home days than oncologists (0%), P = .09. Caregivers reported altruism guided their responses, and clinicians' responses in stated-preference work may differ from revealed-preferences in the clinic. By empirically deriving MCID/NIM for home days and evaluating treatment acceptance, this work will aid trial design and decision studies using an endpoint of home days.