The effect of presenting symptoms and patient characteristics on prehospital delay in MI patients presenting to emergency department by ambulance: a cohort study.
BACKGROUND
There is little recent information about prehospital delay time for Australian patients with myocardial infarction (MI).


OBJECTIVE
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 2.2hours; decreased delay was associated with age <70 years, presenting with chest pain, and diaphoresis. Increased delay was associated with being with a primary health care provider, and if the patient was at home and if the person who called the ambulance was anyone other than the spouse. For 174 patients with non-numeric onset-times, 37% patients delayed one to three days and 110 (64.0%) patients described their symptoms as intermittent and/or of gradual onset.


CONCLUSIONS
Given that prehospital delay times remain longer than is optimal, public awareness of MI symptoms should be enhanced in order to decrease prehospital delay.
School of Population Health, The University of Western Australia, Perth, WA, 6009; Discipline of Emergency Medicine, School of Primary, Aboriginal and Rural Health Care, The University of Western Australia, Perth, WA, 6009; Faculty of Health, Engineering and Science, School of Nursing and Midwifery, Edith Cowan University, Perth, WA, 6027. Electronic address: linda.coventry@ecu.edu.au.
Linda L
LL
Coventry
School of Population Health, The University of Western Australia, Perth, WA, 6009. Electronic address: Alexandra.bremner@uwa.edu.au.
Alexandra P
AP
Bremner
Discipline of Emergency Medicine, School of Primary, Aboriginal and Rural Health Care, The University of Western Australia, Perth, WA, 6009; St John Ambulance, Western Australia, Perth, WA, 6984; Prehospital, Resuscitation and Emergency Care Research Unit, School of Nursing and Midwifery, Curtin University, Perth, WA, 6845. Electronic address: teresa.williams@curtin.edu.au.
Teresa A
TA
Williams
Discipline of Emergency Medicine, School of Primary, Aboriginal and Rural Health Care, The University of Western Australia, Perth, WA, 6009. Electronic address: tony.celenza@uwa.edu.au.
Antonio
A
Celenza
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000552:Ambulances; D001315:Australia; D002637:Chest Pain / Q000209:etiology; D059026:Diagnostic Self Evaluation; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000628:therapy*; D010342:Patient Acceptance of Health Care; D012189:Retrospective Studies; D013546:Sweating; D063189:Symptom Assessment; D061665:Time-to-Treatment
Emergency Department; Emergency medical service; Myocardial infarction; Prehospital delay; Symptom presentation