Evidence of availability bias in diagnostic reasoning following real clinical encounters: a cross-sectional survey of physicians

BACKGROUND: Diagnostic errors remain a significant challenge in healthcare, with cognitive biases, particularly availability bias, playing a critical role. While previous studies focused on controlled experimental settings, this study investigates the real-world impact of clinical practice on susceptibility to the availability bias. METHODS: Using a cross-sectional survey-based design, we assessed 1015 physicians' responses to clinical cases in the form of vignettes after they attended (vs did not attend) a patient with the disease of interest in the last 7 days. Physicians' specialisations and years of experience were also measured, allowing us to assess the presence of the availability bias and the interacting roles of clinical experience and expertise. RESULTS: Recent clinical encounters with a disease increased the likelihood of erroneously diagnosing it (availability bias, b=0.165, SE=0.070, p=0.018). Among specialists, having 10 or more years of experience decreased the likelihood of an erroneous diagnostic (b=-0.361, SE=0.180, p=0.046). The results indicated distinct effects of experience and specialisation on susceptibility to the availability bias. CONCLUSIONS: Availability bias can be triggered by real clinical encounters and is modulated by the interplay between experience and domain-specific expertise. Structured, feedback-rich exposure-rather than mere experience-appears crucial to mitigating cognitive biases. These findings reinforce the role of knowledge-both formal and experiential-in mitigating the bias, and the importance of developing true expertise.