Patients' self-interested preferences: empirical evidence from a priority setting experiment.

This paper explores whether patients act according to self-interest in priority setting experiments. The analysis is based on a ranking experiment, conducted in Galicia (Spain), to elicit preferences regarding the prioritization of patients on a waiting list for an elective surgical intervention (prostatectomy for benign prostatic hyperplasia). Participants were patients awaiting a similar intervention and members of the general populations. All of them were asked to rank hypothetical patients on a waiting list. A rank-ordered logit was then applied to their responses in order to obtain a prioritization scoring system. Using these estimations, we first test for differences in preferences between patients and general population. Second, we implement a procedure based on the similarity between respondents (true patients) and the hypothetical scenarios they evaluate (hypothetical patients) to analyze whether patients provide self-interested rankings. Our results show that patient preferences differ significantly from general population preferences. The findings also indicate that, when patients rank the hypothetical scenarios on the waiting list, they consider not only the explicit attributes but also the similarity of each scenario to their own. In particular, they assign a higher priority to scenarios that more closely match their own states. We also find that such a preference structure increases their likelihood of reporting "irrational" answers.