Cognitive Psychology of Missed Diagnoses

IN RESPONSE:

Dr. Derauf provides some insightful feedback in a kindly manner. His introduction of another maxim is particularly welcome, as are his remarks about the role of confidence in medicine. In moderation, confidence is necessary because facing trouble requires courage, the stakes in medical care are high, and clinicians do not want to act capriciously. Taken to extremes, however, any self-deception is a source of fallibility. A valid rationale is what distinguishes confidence from self-deception.

Psychology research also shows that people sometimes are overly dependent on rationale. In one study (1), students were offered an attractive vacation following a tough examination. By random assignment, one third were told they had passed the examination; in this case, most accepted the offer (presumably as a reward). One third were told they had failed; in this case, most still accepted the offer (presumably as a consolation). The final third were told the examination results were delayed; in this case, most declined the offer. Apparently, the lack of a rationale dissuaded some students from accepting a vacation that was otherwise attractive regardless of circumstance. The general pattern is that even minor decisions require the presence of a rationale.

Biology is complex, and patient presentations are uncertain; hence, a clinician may seek or construct all sorts of rationales. Once a rationale is obtained, such clinicians tend to lack the circumspection of dispassionate reviewers. As Dr. Derauf mentions, self-deception underpins a basic vulnerability to framing effects and a failure to intercept errors. As Dr. Derauf also emphasizes, self-deception is sometimes reinforced by the patient. Alas, self-deception is a resource many of us have in abundance.