Should Aggregate Patient Preference Data Be Used to Make Decisions on Behalf of Unrepresented Patients?

Patient preference predictors aim to solve the moral problem of making treatment decisions on behalf of incapacitated patients. This commentary on a case of an unrepresented patient at the end of life considers 3 related problems of such predictors: the problem of restricting the scope of inputs to the models (the "scope" problem), the problem of weighing inputs against one another (the "weight" problem), and the problem of multiple reasonable solutions to the scope and weight problems (the "multiple reasonable models" problem). Each of these problems poses challenges to reliably implementing patient preference predictors in important, high-stakes health care decision making. This commentary also suggests a way forward.