Medical decision making in situations that offer multiple alternatives.

OBJECTIVE: To determine whether situations involving multiple options can paradoxically influence people to choose an option that would have been declined if fewer options were available. DESIGN: Mailed survey containing medical scenarios formulated in one of two versions. PARTICIPANTS: Two groups of physicians: members of the Ontario College of Family Physicians (response rate = 77%; n = 287) and neurologists and neurosurgeons affiliated with the North American Symptomatic Carotid Endarterectomy Trial (response rate = 84%; n = 352). One group of legislators belonging to the Ontario Provincial Parliament (response rate = 32%; n = 41). INTERVENTION: The basic version of each scenario presented a choice between two options. The expanded version presented three options: the original two plus a third. The two versions otherwise contained identical information and were randomly assigned. OUTCOME MEASURES: Participants treatment recommendations. RESULTS: In one scenario involving a patient with osteoarthritis, family physicians were less likely to prescribe a medication when deciding between two medications than when deciding about only one medication (53% vs 72%; P < .005). Apparently, the difficulty in deciding between the two medications led some physicians to recommend not starting either. Similar discrepancies were found in decisions made by neurologists and neurosurgeons concerning carotid artery surgery and by legislators concerning hospital closures. CONCLUSIONS: The introduction of additional options can increase decision difficulty and, hence, the tendency to choose a distinctive option or maintain the status quo. Awareness of this cognitive bias may lead to improved decision making in complex medical situations.