Martine Nurek, Olga Kostopoulou and York Hagmayer

Predecisional information distortion in physiciansʼ diagnostic judgments: Strengthening a leading hypothesis or weakening its competitor?

Judgment and Decision Making

Decision makers have been found to bias their interpretation of incoming information to support an emerging judgment (predecisional information distortion). This is a robust finding in human judgment, and was recently also established and measured in physiciansʼ diagnostic judgments (Kostopoulou et al. 2012). The two studies reported here extend this work by addressing the constituent modes of distortion in physicians. Specifically, we studied whether and to what extent physicians distort information to strengthen their leading diagnosis and/or to weaken a competing diagnosis. We used the 'stepwise evolution of preference' method with three clinical scenarios, and measured distortion on separate rating scales, one for each of the two competing diagnoses per scenario. In Study 1, distortion in an experimental group was measured against the responses of a separate control group. In Study 2, distortion in a new experimental group was measured against participantsʼ own, personal responses provided under control conditions, with the two response conditions separated by a month. The two studies produced consistent results. On average, we found considerable distortion of information to weaken the trailing diagnosis but little distortion to strengthen the leading diagnosis. We also found individual differences in the tendency to engage in either mode of distortion. Given that two recent studies found both modes of distortion in lay preference (Blanchard, Carlson & Meloy, 2014; DeKay, Miller, Schley & Erford, 2014), we suggest that predecisional information distortion is affected by participant and task characteristics. Our findings contribute to the growing research on the different modes of predecisional distortion and their stability to methodological variation. (PsycINFO Database Record (c) 2016 APA, all rights reserved)

Sponsor: National Institute for Health Research, Biomedical Research Centre, United Kingdom. Other Details: Guyʼs and St Thomasʼ NHS Foundation Trust and Kingʼs College London. Recipients: No recipient indicated