Choice-Matching Preference Reversals in Health Outcome Assessments

Background. Health outcome utility assessments generally assume procedural invariance. Preference reversals violating procedural invariance occur in economic scenarios when the assessment process shifts from a choiceto a fill-in-the-blanktask. Purpose. To determine if similar reversals occur in utility assessments. Methods. One hundred thirty-six volunteer subjects completed 6 preference assessments of 4 personal health scenarios. Patients responded to otherwise identical tasks using either choice or fill-in-the-blank processes in a randomized crossover design. The authors determined the percentage of subjects preferring, or inferred to prefer, a given choice. Results. Preference reversals occurred in all assessment scenarios. Conclusions. These preference reversals are a potential source of confusion for utility assessment and informed consent. They could be manipulated to achieve ends other than the best interest of patients. Anchoring or the prominence hypothesis may explain these findings.