When COVID Became the Answer: ER's Narrow Focus and Missed Diagnoses
A real-world example of Attentional bias in action
Context
During a six-month regional COVID surge, a busy emergency department (ED) saw volumes double and clinicians were repeatedly exposed to patients with fever, cough, and shortness of breath. Triage protocols and media attention amplified the team's preoccupation with COVID as the default diagnosis.
Situation
Over a 6-month period, dozens of patients presented to the ED with respiratory symptoms. Because COVID testing, isolation procedures, and cohorting consumed clinical attention and workflow, alternative causes were less actively considered during initial assessment.
The bias in action
Physicians and triage nurses gave disproportionate attention to features they associated with COVID (fever, cough, oxygen desaturation) and treated those as confirming evidence, while discounting atypical signs and risk factors for other conditions (e.g., unilateral leg swelling, history of atrial fibrillation). Diagnostic imaging (CT pulmonary angiogram, BNP, cardiac enzymes) and specialty consults were ordered less frequently at first, and confirmation searches focused on COVID PCR results rather than broader differential diagnoses. Recurrent thoughts about infection control and patient cohorting reinforced the team's tunnel vision, causing them to miss or delay consideration of pulmonary embolism, heart failure exacerbations, and bacterial sepsis.
Outcome
As a result, a nontrivial number of patients experienced delayed diagnosis and escalation of care. Several who initially received COVID-focused management later required ICU transfer after the correct diagnosis was established. The ED's throughput slowed because mis-triaged patients needed additional workups and transfers once their conditions deteriorated.