An assessment of emergency medical technicians' performance as related to seasonal population influx.

The periodic influx of large numbers of people into resort areas substantially increases the use of emergency medical services. This investigation assesses the effects of such a threefold increase in the summer population of the Cape Cod area upon the accuracy of emergency medical technicians' diagnoses and treatments. The technicians' diagnoses for ambulance patients were evaluated against those given by the emergency room physicians during the months of August 1975 and February 1976. The distribution of conditions was similar for both months and the observed frequency of correct diagnoses for common conditions was more than 90% in both months. The overdiagnosis rate of 25% to 50% for common conditions and the correct treatment rate for suspected myocardial infarction of 65% did not vary significantly between summer and winter. Thus, a large influx in population does not seem to affect adversely EMT diagnosis rates. Although misdiagnoses were uncommon, a failure to follow through with a correct treatment for patients with suspected myocardial infarctions, thus indicating the need for better quality control on EMT performance.