Missed diagnoses of acute myocardial infarction in the emergency department: variation by patient and facility characteristics

Background: An estimated 1.2 million people in the US have an acute myocardial infarction (AMI) each year. An estimated 7% of AMI hospitalizations result in death. Most patients experiencing acute coronary symptoms, such as unstable angina, visit an emergency department (ED). Some patients hospitalized with AMI after a treat-and-release ED visit likely represent missed opportunities for correct diagnosis and treatment. The purpose of the present study is to estimate the frequency of missed AMI or its precursors in the ED by examining use of EDs prior to hospitalization for AMI. Methods: We estimated the rate of probable missed diagnoses in EDs in the week before hospitalization for AMI and examined associated factors. We used Healthcare Cost and Utilization Project State Inpatient Databases and State Emergency Department Databases for 2007 to evaluate missed diagnoses in 111,973 admitted patients aged 18 years and older. Results: We identified missed diagnoses in the ED for 993 of 112,000 patients (0.9% of all AMI admissions). These patients had visited an ED with chest pain or cardiac conditions, were released, and were subsequently admitted for AMI within 7 days. Higher odds of having missed diagnoses were associated with being younger and of Black race. Hospital teaching status, availability of cardiac catheterization, high ED admission rates, high inpatient occupancy rates, and urban location were associated with lower odds of missed diagnoses. Conclusions: Administrative data provide robust information that may help EDs identify populations at risk of experiencing a missed diagnosis, address disparities, and reduce diagnostic errors.