The information distortion bias: implications for medical decisions

Every diagnosis involves an act of decision making, which requires proper evaluation of information. However, even seemingly objective information can require interpretation, often without our conscious awareness. In this cross-cutting edge article we describe the phenomenon of leader-driven information distortion (ID) and its implications for medical education.

Recent research indicates that one threat to good decisions is a biased interpretation of information to favour one alternative course of action over another. Once an alternative emerges as a leader during a decision there is a strong tendency to evaluate subsequent information as supporting that option. This can occur when deciding between two competing diagnoses. It is particularly a concern if diagnostic tests provide potentially ambiguous results. This leader-driven ID is pre-decisional in nature, in that it develops during a decision and involves the interpretation of information available prior to the final decision or diagnosis, with different interpretations possible depending on whichever alternative is the leader. Studies reveal that the distortion bias is pervasive in decisions, and that awareness of the act of distortion is low in decision makers.

Empirical research has confirmed the presence of leader-driven ID in hypothetical diagnoses made by physicians. ID creates two threats to medical decisions: First, it can make a diagnosis sticky in that it is resistant to being overturned by contradictory information. Second, it can promote unwarranted certainty in a diagnosis. The outcome may be premature closure, unnecessary testing or incorrect treatment, resulting in delayed or missed diagnoses.

This paper summarises research related to leader-driven ID in medical and professional decisions and discusses various approaches directed towards reducing ID. A framework and language are provided for thinking about and discussing ID in medical decisions and medical education. Courses of action for mitigating the effects of ID are suggested.