Specific Disease Knowledge as Predictor of Susceptibility to Availability Bias in Diagnostic Reasoning: a Randomized Controlled Experiment

Sílvia Mamede,Stephanie C E Schuit,Marco Antonio De Carvalho Filho,Marco Goeijenbier,Laura Zwaan,Henk G Schmidt,Justine Staal

doi:10.1007/s11606-020-06182-6

Abstract

BackgroundBias in reasoning rather than knowledge gaps has been identified as the origin of most diagnostic errors. However, the role of knowledge in counteracting bias is unclear.ObjectiveTo examine whether knowledge of discriminating features (findings that discriminate between look-alike diseases) predicts susceptibility to bias.DesignThree-phase randomized experiment. Phase 1 (bias-inducing): Participants were exposed to a set of clinical cases (either hepatitis-IBD or AMI-encephalopathy). Phase 2 (diagnosis): All participants diagnosed the same cases; 4 resembled hepatitis-IBD, 4 AMI-encephalopathy (but all with different diagnoses). Availability bias was expected in the 4 cases similar to those encountered in phase 1. Phase 3 (knowledge evaluation): For each disease, participants decided (max. 2 s) which of 24 findings was associated with the disease. Accuracy of decisions on discriminating features, taken as a measure of knowledge, was expected to predict susceptibility to bias.ParticipantsInternal medicine residents at Erasmus MC, Netherlands.Main MeasuresThe frequency with which higher-knowledge and lower-knowledge physicians gave biased diagnoses based on phase 1 exposure (range 0–4). Time to diagnose was also measured.Key ResultsSixty-two physicians participated. Higher-knowledge physicians yielded to availability bias less often than lower-knowledge physicians (0.35 vs 0.97; p = 0.001; difference, 0.62 [95% CI, 0.28–0.95]). Whereas lower-knowledge physicians tended to make more of these errors on subjected-to-bias than on not-subjected-to-bias cases (p = 0.06; difference, 0.35 [CI, − 0.02–0.73]), higher-knowledge physicians resisted the bias (p = 0.28). Both groups spent more time to diagnose subjected-to-bias than not-subjected-to-bias cases (p = 0.04), without differences between groups.ConclusionsKnowledge of features that discriminate between look-alike diseases reduced susceptibility to bias in a simulated setting. Reflecting further may be required to overcome bias, but succeeding depends on having the appropriate knowledge. Future research should examine whether the findings apply to real practice and to more experienced physicians.

Highlights

A National Academy of Medicine report recently emphasized that diagnostic errors may be one of the most common and most harmful of patient safety problems.[1]
In phase 1, participants evaluated the plausibility of a diagnosis given for clinical cases from one of two case sets
Previous exposure to a disease that looks like the case at hand was expected to induce availability bias, causing diagnostic errors in the 4 cases of phase 2 that resembled the ones encountered in phase 1

Summary

Introduction

A National Academy of Medicine report recently emphasized that diagnostic errors may be one of the most common and most harmful of patient safety problems.[1]. Behind most flaws would be biases induced by heuristics[5] routinely used by physicians to make fast, intuitive judgments.[6,7,8,9] For instance, physicians tend to focus on considering diagnoses that are more retrievable from memory. Though efficient, this may lead to “availability bias” when what comes more to mind is an incorrect diagnosis.[10, 11] This viewpoint seems supported by retrospective studies.

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