Factors that influence the use of ambulance in acute coronary syndrome.
BACKGROUND
National guidelines recommend activation of the emergency medical service by patients who have symptoms of acute coronary syndrome (ACS). In spite of this, only 50% to 60% of persons with myocardial infarction initiate care by using the emergency medical service. The aim of this study was to define factors influencing the use of ambulance in ACS.


METHODS
The method used in this study was a national survey comprising intensive cardiac care units at 11 hospitals in Sweden; 1,939 patients with diagnosed ACS and symptom onset outside the hospital completed a questionnaire a few days after admission.


RESULTS
Half of the patients went to the hospital by ambulance. Factors associated with ambulance use were knowledge of the importance of quickly seeking medical care and calling for an ambulance when having chest pain (odds ratio [OR] 3.61, 95% CI 2.43-5.45), abrupt onset of pain reaching maximum intensity within minutes (OR 2.08, 1.62-2.69), nausea or cold sweat (OR 2.02, 1.54-2.65), vertigo or near syncope (OR 1.63, 1.21-2.20), ST-elevation ACS (OR 1.58, 1.21-2.06), increasing age (per year) (OR 1.03, 1.02-1.04), previous history of heart failure (OR 2.48, 1.47-4.26), and distance to the hospital of >5 km (OR 2.0, 1.55-2.59). Those who did not call for an ambulance thought self-transport would be faster or did not believe they were sick enough.


CONCLUSIONS
Symptoms, patient characteristics, ACS characteristics, and perceptions and knowledge were all associated with ambulance use in ACS. The fact that knowledge increases ambulance use and the need for behavioral change pose a challenge for health-care professionals.
Thuresson
Marie
M
Division of Cardiology, Orebro University Hospital, School of Health and Medical Sciences, Orebro, Sweden. marie.thuresson@swipnet.se
Jarlöv
Marianne Berglin
MB
Lindahl
Bertil
B
Svensson
Leif
L
Zedigh
Crister
C
Herlitz
Johan
J
D054058:Acute Coronary Syndrome / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000552:Ambulances / Q000592:standards / Q000706:statistics & numerical data*; D004562:Electrocardiography; D004632:Emergency Medical Services / Q000592:standards* / Q000706:statistics & numerical data; D005260:Female; D017408:Guidelines as Topic; D019538:Health Care Surveys; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011336:Probability; D011787:Quality of Health Care; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016019:Survival Analysis; D013548:Sweden; D013997:Time Factors; D014187:Transportation of Patients / Q000592:standards / Q000706:statistics & numerical data