Availability Bias Causes Misdiagnoses by Physicians: Direct Evidence from a Randomized Controlled Trial

Area of Science:

• Medical Education
• Cognitive Psychology
• Clinical Diagnostics

Background:

• Availability bias, a cognitive heuristic, can influence clinical judgment.
• Empirical evidence on availability bias contributing to diagnostic errors is limited.
• The effectiveness of reflective reasoning in mitigating such biases requires further investigation.

Purpose of the Study:

• To determine if recent clinical exposure increases diagnostic errors via availability bias.
• To assess whether reflective reasoning can counteract availability bias in medical diagnoses.
• To provide empirical evidence on the impact of cognitive biases in medical decision-making.

Main Methods:

• Forty-six internal medicine residents were randomized into control and experimental groups.
• The experimental group received information on dengue fever (DF) prior to case diagnosis.
• Participants diagnosed clinical cases using nonanalytic and reflective reasoning.

Main Results:

• The experimental group showed no significant difference in diagnostic scores between experimental and filler cases, unlike the control group.
• A high proportion of experimental cases were incorrectly diagnosed as DF by the experimental group (71%-100%).
• Reflective reasoning did not significantly improve diagnostic accuracy compared to nonanalytic reasoning.

Conclusions:

• Availability bias, triggered by recent information, demonstrably leads to diagnostic errors.
• Reflective approaches alone are insufficient to fully correct misdiagnoses stemming from availability bias.
• Cognitive biases pose a significant challenge to accurate clinical diagnosis, even with reflective strategies.