Community trends in the use and characteristics of persons with acute myocardial infarction who are transported by emergency medical services

OBJECTIVE: Limited data exist on recent trends in ambulance use and factors associated with ambulance use in patients hospitalized with acute myocardial infarction (AMI), particularly from the more generalizable perspective of a community-wide investigation. This population-based prospective epidemiologic study describes the decade-long trends (1997-2007) in the use of emergency medical services (EMS) by residents of the Worcester, Massachusetts, metropolitan area who are hospitalized for AMI and the characteristics of patients with AMI who are transported to the hospital by EMS (n = 3789) compared with those transported by other means (n = 1505). METHODS: The study population consisted of 5294 patients hospitalized for AMI at 11 greater Worcester medical centers in 5 annual periods between 1997 and 2007. Information on the use of EMS and the factors associated with EMS use was obtained through the review of hospital medical records. RESULTS: There was a progressive increase in the proportion of greater Worcester residents with AMI who were transported to central Massachusetts hospitals by ambulance over time (66.9% transported in 1997; 74.9% transported in 2007). Patients transported by EMS were older, more likely to be women, and more likely to have a greater prevalence of previously diagnosed comorbidities. CONCLUSION: Our findings provide encouragement for the use of EMS in residents of a large central New England community hospitalized with AMI. Despite increasing trends in ambulance use, more research is needed to explore the reasons why patients with AMI do not use EMS in the setting of an acute cardiac emergency.