Cognitive Biases in Orthopaedic Surgery

INTRODUCTION: Cognitive biases are known to affect all aspects of human decision-making and reasoning. Examples include misjudgment of probability, preferential attention to evidence that confirms one's beliefs, and preference for certainty. It is not known whether cognitive biases influence orthopaedic surgeon decision-making. This study measured the influence of a few cognitive biases on orthopaedic decision-making in hypothetical vignettes. The questions we addressed were as follows: Do orthopaedic surgeons display the cognitive biases of base rate neglect and confirmation bias in hypothetical vignettes? Can anchoring and framing biases be demonstrated? METHODS: One hundred ninety-six orthopaedic surgeons completed a survey consisting of three vignettes evaluating base rate neglect, five evaluating confirmation bias, and two separate vignettes each randomly exposing half of the group to different anchors and frames. RESULTS: For the three vignettes evaluating base rate neglect, 43% (84 of 196) chose answers consistent with base rate neglect in vignette 1, 88% (173 of 196) in vignette 2, and 35% (69 of 196) in vignette 3. Regarding confirmation bias, 51% (100 of 196) chose an answer consistent with confirmation bias for vignette 1, 11% (22 of 196) for vignette 2, 22% (43 of 196) for vignette 3, 22% (44 of 196) for vignette 4, and 29% (56 of 196) for vignette 5. There was a measurable anchoring heuristic (56% versus 34%; a difference of 22%) and framing effect (77% versus 61%; a difference of 16%). CONCLUSION: The influence of cognitive biases can be documented in patient vignettes presented to orthopaedic surgeons. Strategies can anticipate cognitive bias and develop practice debiasing strategies to limit potential error.