The Effect of Ambulance Staffing Models in a Metropolitan, Fire-Based EMS System

Introduction The staffing of ambulances with different levels of Emergency Medical Service (EMS) providers is a difficult decision with evidence being mixed on the benefit of each model. Hypothesis/Problem The objective of this study was to describe a pilot program evaluating alternative staffing on two ambulances utilizing the paramedic-basic (PB) model (staffed with one paramedic and one emergency medical technician[EMT]).

This was a retrospective study conducted from September 17, 2013 through December 31, 2013. The PB ambulances were compared to geographically matched ambulances staffed with paramedic-paramedic (PP ambulances). One PP and one PB ambulance were based at Station A; one PP and one PB ambulance were based at Station B. The primary outcome was total on-scene time. Secondary outcomes included time-to-electrocardiogram (EKG), time-to-intravenous (IV) line insertion, IV-line success rate, and percentage of protocol violations. Inclusion criteria were all patients requesting prehospital services that were attended to by these teams. Patients were excluded if they were not attended to by the study ambulance vehicles. Descriptive statistics were reported as medians and interquartile ranges (IQR). Proportions were reported with 95% confidence intervals (CI). The Mann-Whitley U test was used for significance testing (P<.05).

Median on-scene times at Station A for the PP ambulance were shorter than the PB ambulance team (PP: 10.1 minutes, IQR 6.0-15; PB: 13.0 minutes, IQR 8.1-18; P=.01). This finding also was noted at Station B (PP: 13.5 minutes, IQR 8.5-19; PB: 14.3 minutes, IQR 9.9-20; P=.01). There were no differences between PP and PB ambulance teams at Station A or Station B in time-to-EKG, time-to-IV insertion, IV success rate, and protocol violation rates.

In the setting of a well-developed EMS system utilizing an all-Advanced Life Support (ALS) response, this study suggests that PB ambulance teams may function well when compared to PP ambulances. Though longer scene times were observed, differences in time to ALS interventions and protocol violation rates were not different. Hybrid ambulance teams may be an effective staffing alternative, but decisions to use this model must address clinical and operational concerns. Cortez EJ , Panchal AR , Davis JE , Keseg DP . The effect of ambulance staffing models in a metropolitan, fire-based EMS system. Prehosp Disaster Med. 2017;32(2):175-179.