Abstract 9550: Regional Variation in Emergency Department Visits for Acute Myocardial Infarction - Nationwide Emergency Department Sample, 2008

Abstract

Background: For the majority of patients with acute myocardial infarction (AMI), the emergency department (ED) is the entry point into the healthcare system. Although previous studies have described regional differences in treatment for AMI, few studies have examined regional variations in ED visits for AMI. Objective: This study sought to describe variations in AMI visits to EDs by Census Bureau-designated regions of the U.S. in 2008 and to examine characteristics of those visits. Methods: ED data from the 2008 Nationwide Emergency Department Sample (NEDS) were analyzed. The NEDS is a stratified random probability sample of hospital-based EDs from community, non-rehabilitation hospitals in the U.S. SUDAAN was used to account for the complex sampling scheme. Only adults (aged ≥ 18 years) were included in the analysis. Visits for AMI were defined as the primary diagnosis listed as International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 410.xx, excluding cases for which the fifth digit was 2 which indicates further evaluation of a recent MI. Rates of AMI ED visits per population were calculated by region using U.S. Census estimates for 2008. Results: In 2008, adults made an estimated 98,515,683 ED visits. Of those, 537,167 (0.6%) had a primary diagnosis of AMI; 84% were admitted to the presenting hospital and 11% were transferred to another short-term hospital. Approximately 1% died in the ED. Men accounted for 59.6% of AMI ED visits. Persons aged ≥ 75 years accounted for 37.4% of AMI visits. More than half of visits (57.2%) were made by Medicare beneficiaries. The majority of visits were made to EDs in urban areas (79.4%). ED visit rates per 10,000 population for each region were: Northeast, 23.9 (95% confidence interval [CI]: 20.6-27.1); Midwest, 24.8 (95% CI: 22.1-27.4); South, 25.7 (95% CI: 23.1-28.2); West 17.9 (15.8-20.0). Women in the West had the lowest rate of AMI visits (13.8 per 10,000) compared to women and men in the other regions. Rates increased by age group for all regions. Conclusions: ED visits for AMI vary significantly by geographic region. The lowest rate of AMI visits per population was noted in the West. Further study is needed to identify the factors that cause these regional variations in ED visits.