Population-based time preferences for future health outcomes

Context Time preference (how preference for an outcome changes depending on when the outcome occurs) affects clinical decisions, but little is known a bout determinants of time preferences in clinical settings. Objectives. To determine whether information about mean population time preferences for sp ecific health states can be easily assessed, whether mean time preferences are constant across different diseases, and whether under certain circumsta nces substantial fractions of the patient population make choices that are consistent with a negative time preference. Design. Self-administered surve y. Setting. Family physician waiting rooms in four states. Patients. A conv enience sample of 169 adults. Intervention. Subjects were presented five cl inical vignettes. For each vignette the subject chose between interventions maximizing a present and a future health outcome. The options for individu al vignettes varied among the patients so that a distribution of responses was obtained across the population of patients. Main outcome measure. Logis tic regression was used to estimate the mean preference for each vignette, which was translated into an implicit discount rate for this group of patie nts. Results. There were marked differences in time preferences for future health outcomes based on the five vignettes, ranging from a negative to a h igh positive (116%) discount rate. Conclusions. The study provides empirica l evidence that time preferences for future health outcomes may vary substa ntially among disease conditions. This is likely because the vignettes evok ed different rationales for time preferences. Time preference is a critical element in patient decision making and cost-effectiveness research, and mo re work is necessary to improve our understanding of patient preferences fo r future health outcomes.