Diagnostic errors lead to death or disability for an estimated 150 000 patients in the United States each year.1 The emergency department is a known high-risk location for misdiagnosis.2 Missed ischemic stroke and brain hemorrhage are recognized sources of diagnostic error, with approximately 9% of cerebrovascular events missed at first emergency department contact,3 including an estimated 20% of subarachnoid hemorrhages in patients presenting with normal mental status.4 Because effective treatments are available, diagnostic delays increase morbidity and mortality 3- to 8-fold,4,5 so accurate early diagnosis is important.
Newman-Toker DE, Edlow JA. High-Stakes Diagnostic Decision Rules for Serious DisordersThe Ottawa Subarachnoid Hemorrhage Rule. JAMA. 2013;310(12):1237-1239. doi:10.1001/jama.2013.278019