Objective: To explore the choice of transportation mode to hospital in patients experiencing acute myocardial infarction.
Method: A descriptive survey study at the Coronary Care Unit of one Swedish University Hospital. The study was carried out between July 2000 and March 2001.
Results: The study population consisted of 114 consecutive patients with acute myocardial infarction. Thirty-two percent stated that they did not know the importance of a short delay when experiencing an acute myocardial infarction. Only 60% called the emergency service number, 112. Patients calling for an ambulance differed from those who did not in several aspects. Medical characteristics associated with ambulance use in a univariate analysis were ST-elevation myocardial infarction and prior history of myocardial infarction. There were no differences regarding gender or age. When looking at the patients' symptom-experience, patients with vertigo or nausea and severe pain chose an ambulance for transport to the hospital. The only significant reasons for not choosing an ambulance were cramping pain and the patient perceiving the symptoms not to be serious. In a multivariate analysis, ST-elevation (OR = 0.30, P = .04), unbearable symptoms (OR = 0.20, P = .03), and nausea (OR = .33, P = .04) appeared as independent predictors of ambulance use and cramping pain (OR = 5.17, P = .01) for not using an ambulance.
Conclusions: Patients with acute myocardial infarction view the ambulance as an option for transportation to hospital only if they feel really sick. For that reason, it needs to be made well known to the public that ambulances are not only a mode of transport, but also provide diagnostics and treatment.
Swedish, 1 as well as European 2 and American 3 guidelines, state that ST-elevation myocardial infarction (STEMI) patients should be treated with thrombolysis in less than 90 minutes after the onset of symptoms. Depending on local circumstances, this may involve direct admission to the coronary care unit (CCU), fast-track assessment in emergency departments, or prehospital treatment. The greatest improvements in survival are in those patients treated most rapidly. 4
Approximately, one- to two-thirds of acute myocardial infarction (MI) cases are fatal before hospital admittance 5,6 and these fatalities most commonly occur within 1 hour of the onset of symptoms. These patients have no opportunity to benefit from the advantages of hospital treatment of acute MI, such as thrombolysis. Therefore, the greatest scope to improve survival lies outside hospital.
A large proportion of the work of paramedics is to care for patients who suffer from suspected MI. Prehospital initiation of thrombolytic therapy by paramedics has been shown to be both feasible and safe. 7 Earlier studies have demonstrated the ability of paramedics to identify ECG changes suggestive of a STEMI 8,9 and most ambulances in Sweden today have ECG-possibilities and telecommunication with the hospital.
In Ostergotland county in Sweden, an area of approximately 10,500 km2 and 415,000 inhabitants, patients with an acute MI can dial the emergency service number and 90% can be reached by an ambulance within 15 minutes. This can be done without contact with a general practitioner (GP). When the paramedics care for a patient with a suspected acute MI, an ECG is taken and transmitted by the mobile telephone network to the CCU and a checklist regarding contraindications for thrombolysis is filled in. It is thus possible, after a telephone decision from a cardiologist, to start early prehospital treatment and/or make a rapid access directly to the CCU, bypassing the emergency department. It is therefore of great importance that patients be aware of the advantages of medical care that paramedics can offer.
Earlier studies, however, have shown that only 30% to 50% of all patients with chest pain arrive at the emergency room by ambulance. 10-13 Patients experiencing an MI who call for an ambulance are different in terms of demographics and clinical characteristics from those who do not. It has been reported that the callers are older, women, have a higher prevalence of previous cardiovascular diseases, and that they suffer from more severe symptoms. 14,15 They also have a higher in-hospital mortality, larger infarcts, and more problems with congestive heart failure. 14 Previous research also suggests that financial factors might influence prehospital behavior in some countries. Data from the United States 10,16 have shown that economic considerations might affect ambulance utilization among underinsured and low-income patients. This is however not a problem in Sweden due to the existing state health insurance system.
The reasons for the underutilization of ambulance transportation by patients with acute MI are still not entirely understood. The aim of this study was therefore to explore the choice of transportation mode when individuals experience symptoms of acute MI.