To date, investigators with little formal research training and minimal funding or other resources have contributed the substance of the literature in prehospital emergency care. Thus, most published research addresses the most austere questions involving single clinical interventions or health issues. Answers to major EMS issues such as cost-effectiveness, resource utilization, efficacy of field therapies, and injury prevention are conspicuous by their absence from the literature. In addition, as in other areas of medicine, there is little research demonstrating effective methods to improve patient safety in EMS by reducing medical errors.
Despite the absence of evidence for the efficacy of almost all field interventions, progress is occurring in several areas. The Ontario Prehospital Advanced Life Support (OPALS) Study is the largest prehospital study ever conducted. It is enrolling more than 25,000 cardiac arrest, trauma, and critically ill patients over an 8-year period (1994-2002). The OPALS study uses a rigorous controlled methodology and a large sample size, and it is designed to measure the benefit in survival and morbidity that results from the introduction of prehospital ALS programs to communities of different sizes.25,26,66 While prehospital clinical studies of that magnitude have not been completed in the United States, some complex, well designed studies have been successfully implemented and completed. A clinical trial of the use of high dose epinephrine67 and the pediatric intubation study from Los Angeles18 are notable examples.