Anchoring Bias: Tales from the Front Line:

A thorough history and awareness of the unexpected help overcome anchoring bias.

Tales from the Front Line: Anchoring Bias

The medical notes say he has a swollen, red, painful wrist. As he is bed-bound, he requires a home visit—the differential lists cellulitis as the most likely diagnosis.  

“Did you hurt your wrist,” I say.

“No”

I look for any scratches or entry points that indicate infection. The notes state the wrist is warm, red, and painful. He has a temperature, but otherwise, his observations are stable. Something doesn’t add up. It does look like he has cellulitis, but there’s no source for the infection. 

In their influential 1974 paper “Judgment under Uncertainty: Heuristics and Biases,” Tversky and Kahneman proposed that when individuals make predictions, they start with an initial value or anchor and adjust their reasoning from that arbitrary point.

Anchoring is a common bias in emergency settings, leading to diagnostic errors. Applying excessive weight to initial information makes adjusting the diagnostic hypothesis challenging even when further informatio…