New evidence of preference reversals in health utility measurement.

A central assumption in health utility measurement is that preferences are invariant to the elicitation method used. This assumption is challenged by preference reversals. Previous studies have observed preference reversals between choice and matching tasks and between choice and ranking tasks. We present a preference reversal that is entirely derived from choices, the basic primitive of economics and utility theory. The preference reversal was observed in two studies regarding health states after stroke. Both studies involved large representative samples from the Spanish population, interviewed professionally, and face-to-face. Possible explanations for the preference reversal are the anticipation of disappointment and elation in risky choice and the impact of ethical considerations about the value of life.