EMPIRICAL EVALUATION OF THE ACCEPTABLE REGRET MODEL OF MEDICAL DECISION- MAKING

Purpose: The acceptable regret model postulates that under specific circumstances decision makers may tolerate wrong decisions (Med Hypotheses, 53, 253-9; PLoS Med, 4, e26; Med Dec Making, 28, 540-553; Med Dec Making, 29, 320-322). The purpose of this work is to empirically evaluate the acceptable regret model of decision-making in end-of-life care settings, where terminally ill patients consider seeking curative treatment or accepting hospice/palliative care.

Method: We conducted interviews with 24 patients enrolled in the study assessing their preferences about end-of –life treatment choices. After providing information about their life expectancy and assessing the overall regret of potentially wrong choices (BMC Med Inform Decis Mak, 10, 51), we elicited the patients’ level of acceptable regret. We first assessed the patients’ tolerance for wrongly accepting hospice care and then measured the patients’ tolerance toward continuing unnecessary treatment. For the purposes of our study, a treatment was considered unnecessary if a patient dies within 6 months of the treatment. Accepting hospice care was considered a wrong decision if a patient survives longer than 6 months after the referral to hospice. We elicited acceptable regret levels to compute: 1) the probability of death above which a patient would tolerate wrongly accepting hospice care and 2) the probability of death below which the patient would tolerate unnecessary treatment (BMC Med Inform Decis Mak, 10, 51; Med Dec Making, 28, 540-553).

Result: We found that the median probability of death above which a decision maker would tolerate wrongly accepting hospice care is 98%, while the median probability of death below which a decision maker would tolerate unnecessary treatment is 4%. We also found that the levels of acceptable regret measured for wrong hospice referral (mean=1.68; SD=2.3; min=0; max=7.28) are similar to the levels of acceptable regret measured for unnecessary treatment (mean=1.27; SD=1.97; min=0; max=6.58) (KW test; p=0.73) indicating that acceptable regret levels for either of wrong decisions is felt similarly. Our results are independent of the estimated probability of death communicated to patients prior to the acceptable regret interview.

Conclusion: We have elicited preliminary empirical data that corroborated the acceptable regret theory. Our results may explain why has been so difficult to provide palliative care in the end of life setting.