Study objectives: To determine whether prehospital outcome of patients who receive care from emergency medical technicians-paramedic (EMT-Ps) differs from that of patients who receive care from emergency medical technicians-defibrillation (EMT-Ds), as rated by the treating EMTs using standardized scales, and to determine whether the patient's seriousness of illness is relevant to any differential benefit of one level of care over the other.
Design: Historical (retrospective) cohort.
Setting: An urban and semiurban region of southwest Ontario comprising an area of 1,136 square kilometers (438 square miles) with a population of more than 445,000.
Type of participants: Patients (10,291) who were transported by the Hamilton-Wentworth EMS system between January 1, 1991, and December 31, 1991.
Methods and measurements: EMTs rated the prehospital outcome of their own patients, using scales that had been tested in a previous study. Comparisons between EMT-P- and EMT-D-treated patients were made by chi 2, chi 2 by trend, and Fisher's exact test as appropriate.
Results: More seriously ill or injured EMT-P-treated patients were rated as improved and fewer EMT-P-treated patients were rated as worsened compared with similar patients who were cared for and rated by EMT-Ds. The differential benefit from EMT-P to EMT-D care ranged from 8% to 25% for patients rated as "severe" and from 27% to 49% for patients rated as "life-threatened."
Conclusion: According to the ratings of prehospital care providers, patients classified as "severe" or "life-threatened" had their conditions "improve" by the time they arrived at the hospital more often when care was provided by an EMT-P team than when it was provided by an EMT-D team.