The prominence effect in health-care priority setting

People often choose the option that is better on the most subjectively prominent attribute — the prominence effect. We studied the effect of prominence in health care priority setting and hypothesized that values related to health would trump values related to costs in treatment choices, even when individuals themselves evaluated different treatment options as equally good. We conducted pre-registered experiments with a diverse Swedish sample and a sample of international experts on priority setting in health care (n = 1348). Participants, acting in the role of policy makers, revealed their valuation for different medical treatments in hypothetical scenarios. Participants were systematically inconsistent between preferences expressed through evaluation in a matching task and preferences expressed through choice. In line with our hypothesis, a large proportion of participants (General population: 92%, Experts 84% of all choices) chose treatment options that were better on the health dimension (lower health risk) despite having previously expressed indifference between those options and others that were better on the cost dimension. Thus, we find strong evidence of a prominence effect in health-care priority setting. Our findings provide a psychological explanation for why opportunity costs (i.e., the value of choices not exercised) are neglected in health care priority setting.