Lit Matters #2: The Impact of Availability Bias on ED Workups

Availability bias measurably changes emergency department workups for shortness of breath. After an ED physician diagnoses pulmonary embolism, PE testing in subsequent dyspnea patients rises transiently, even in a setting with decision rules and relatively lower medicolegal pressure.

Availability Bias in PE Workups

• Transient post-PE testing spike: A recent pulmonary embolism diagnosis nudges the next dyspnea workups toward more D-dimer and CTPA use, with about a 15% relative increase in PE testing over the next 10 days.
• Signal despite decision rules: This effect showed up in PE, a diagnosis already supported by tools like Wells and PERC, suggesting cognitive bias persists even when structured risk stratification exists.
• Short-lived recency effect: The testing increase was not permanent; it drifted back toward baseline over the following weeks, a practical reminder that recent memorable cases can temporarily reshape pretest probability.
• Built-in negative controls: The study compared PE testing changes with unrelated orders like TSH and hand radiographs, strengthening the case that the shift reflected availability bias rather than a general tendency to overtest.
• Why this likely matters more: A VA-based cohort may underestimate the real-world effect, since broader ED practice includes more medicolegal pressure and additional PE risk contexts. We get into the bedside implications in the episode.