Teammate Familiarity, Teamwork, and Risk of Workplace Injury in Emergency Medical Services Teams.

INTRODUCTION Increased teammate familiarity in emergency medical services (EMS) promotes development of positive teamwork and protects against workplace injury. METHODS Measures were collected using archival shift records, workplace injury data, and cross-sectional surveys from a nationally representative sample of 14 EMS agencies employing paramedics, prehospital nurses, and other EMS clinicians. One thousand EMS clinicians were selected at random to complete a teamwork survey for each of their recent partnerships and tested the hypothesized role of teamwork as a mediator in the relationship between teammate familiarity and injury with the PROCESS macro. RESULTS We received 2566 completed surveys from 333 clinicians, of which 297 were retained. Mean participation was 40.5% (standard deviation [SD] = 20.5%) across EMS agencies. Survey respondents were primarily white (93.8%), male (67.3%), and ranged between 21-62 years of age (M = 37.4, SD = 9.7). Seventeen percent were prehospital nurses. Respondents worked a mean of 3 shifts with recent teammates in the 8 weeks preceding the survey (M = 3.06, SD = 4.4). We examined data at the team level, which suggest positive views of teamwork (M = 5.92, SD = 0.69). Our hypothesis that increased teammate familiarity protects against adverse safety outcomes through development of positive teamwork was not supported. Teamwork factor Partner Adaptability and Backup Behavior is a likely mediator (odds ratio = 1.03, P = .05). When dyad familiarity is high and there are high levels of backup behavior, the likelihood of injury is increased. DISCUSSION The relationship between teammate familiarity and outcomes is complex. Teammate adaptation and backup behavior is a likely mediator of this relationship in EMS teams with greater familiarity.