Purpose: In the era of evidence-based medicine and shared decision making, the formal assessment of patient preference for treatments or treatment outcomes has attracted much attention. In this article, the two most common approaches to the evaluation of preference, ie, utility assessment and probability trade-off assessment, are described. The purpose is to provide clinicians with the background knowledge needed to interpret preference studies published in the literature and to judge whether the reported findings are relevant to their own patients.
Methods: An overview is given of the methods used to assess utilities and probability trade-off scores. Evidence on determinants of such scores is presented. Examples from oncology are provided. Because experience with the treatment plays an important role as a determinant of preferences for both treatments and treatment outcomes, special attention is paid to the interpretation of studies in the light of subject selection. Directions for future research are suggested.
Conclusion: The choice of approach and the measuring instrument depend on the goal of the preference assessment. Normal psychologic processes, such as coping, adaptation, and cognitive dissonance reduction, cause patients who are about to undergo a therapy or have experienced a therapy to rate it more favorably than other patients do. This should be remembered when using evidence from the literature to inform patients or for patient decision making.