The Effect of Presenting Symptoms and Patient Characteristics on Prehospital Delay in MI Patients Presenting to Emergency Department by Ambulance: A Cohort Study

Introduction There is little recent information about prehospital delay time for Australian patients with myocardial infarction (MI). Objectives This study: (1) describes prehospital delay time for patients with MI; (2) identifies variables and presenting symptoms which contribute to the delay. Methods This retrospective cohort study identified patients with an Emergency Department (ED) discharge diagnosis of MI, transported by ambulance to one of the seven Perth metropolitan EDs, between January 2008 and October 2009. Prehospital delay times were analysed using linear regression models. Non-numeric (word descriptions) of delay time were categorised. Results Of 1,633 patients, symptom onset-time was available for 1,003. For 829 patients with a numeric onset-time, median delay was 2.2 hours; decreased delay was associated with age