Individual Differences, Expertise and Outcome Bias in Medical Decision Making

AbstractOutcome bias describes the tendency of people to alter their rating of a decision’s quality according to whether the outcome is good or bad – despite equivalencies in available information and decision processes – which has the potential to undermine learning about causal structures and diagnostic information in many fields, including medicine. Herein, a sample of 181 doctors and medical students is shown to display outcome bias in medical and non-medical scenarios – with their susceptibility correlating across the domains, r = 0.38. Analyses showed that rational and intuitive decision styles and a medical risk tolerance measure offered little predictive power. Instead, the strongest drivers of bias susceptibility were the Age and professional Level of participants, with more senior personnel showing less outcome bias. We argue that this could reflect improved learning across a doctor’s career or result from increasing confidence making them less likely to change their initial judgement of decision quality.


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