This case describes an older adult patient with generalized abdominal pain who was eventually diagnosed with inoperable bowel necrosis. Although she appeared well and had stable vital signs, triage was delayed due to emergency department (ED) crowding, which is usually a result of hospital crowding. She was under-triaged and waited three hours before any diagnostic studies or interventions commenced. Once she was placed on a hallway gurney laboratory and imaging studies proceeded hastily.

A 65-year-old man with metastatic liver disease presented to the hospital with worsening abdominal pain after a partial hepatectomy and development of a large ventral hernia. Imaging studies revealed perforated diverticulitis. A goals-of-care discussion was led by the palliative care service; the patient and his designated decision-makers chose to pursue non-operative management of diverticulitis.

Diagnostic error has been increasingly recognized as an important and evolving patient safety issue. This Primer applies well-established principles of diagnostic error and improvement of diagnostic accuracy to the topic of COVID-19.