Implementation of a pre-hospital decision rule in general practice. Triage of patients with suspected myocardial infarction.

OBJECTIVE

To improve pre-hospital triage of patients with suspected acute cardiac disease.

DESIGN

Prospective study. SUBJECTS. Patients with symptoms suggestive of acute cardiac pathology, who were seen by a general practitioner, for whom acute admission into hospital was requested, and in whom a pre-hospital electrocardiogram was recorded by the ambulance service.

METHODS

The study consisted of two phases. In the first phase, a decision rule was developed based on clinical characteristics and electrocardiographic findings in 1005 patients with suspected acute cardiac pathology. In the second phase, the decision rule was prospectively validated. Symptoms were recorded by a standardized questionnaire by the general practitioner and a computerized electrocardiogram was made by the ambulance nurses at the patient's home. Three electrocardiographic outcomes were available: 'normal electrocardiogram', 'possible myocardial infarction' or 'extensive myocardial infarction'. By use of the predictive model, the general practitioner could decide if hospitalization was necessary or not.

MAIN OUTCOME MEASUREMENTS

Identification of patients at low (stable angina, atypical chest pain, other pathology) and high (myocardial infarction, unstable angina) probability of acute cardiac pathology.

RESULTS

Among 977 patients with a complete pre-hospital evaluation in the validation phase of the study, the decision rule recommended 'no hospitalization' in 227 patients (23%). The general practitioner followed this advice in 44% of these patients. Although seven of them developed a non-Q wave myocardial infarction, no complications occurred in patients not admitted. In addition, the general practitioner did not hospitalize 19 (2%) of 750 patients for whom the decision rule recommended admission. Pre-hospital triage by the general practitioner resulted in a 12% (118 of 977 patients) reduction of the number of patients admitted to the Coronary Care Units.

CONCLUSIONS

Pre-hospital triage by the general practitioner was facilitated using a standardized questionnaire and pre-hospital electrocardiography, and resulted in a reduction in the number of patients admitted to the Coronary Care Unit, and proved to be safe.