How Adjusting Elicited Health Utilities after the Fact can Adversely Affect Shared Decision Making

Background: The elicitation of inconsistent health-state utility values (HSUVs) is a prevalent problem. There are two approaches to address this problem: (1) intervention during the elicitation process to ensure that patients estimate consistent HSUVs; (2) no intervention during the elicitation process and inconsistent HSUVs are adjusted after the fact. This paper studies three models recently proposed for adjusting inconsistent HSUVs and consistent HSUVs that some may consider unrealistic. Analysis: The three models are analyzed using a sound theoretical framework: the mathematical equivalence of HSUVs elicited using the standard gamble and probabilities, the Fréchet bounds, and preference theory. It is proven that none of these models accounts for the Fréchet lower bound and health conditions that are preference substitutes. Results: A clinical vignette proves these models may recommend treatments that result in premature death over treatments that cause acceptable adverse effects. Conclusions: The three models are incorrect and may mislead patients and physicians to poor medical decisions. In the spirit of shared decision making, patients should be given the opportunity to reassess inconsistent HSUVs and confirm that the revised HSUVs reflect their preferences.