The Association Between the Number of Prehospital Providers On-Scene and Out-of-Hospital Cardiac Arrest Outcomes.

The ideal number of emergency medical services (EMS) providers needed on-scene during an out-of-hospital cardiac arrest (OHCA) resuscitation is unknown. Our objective was to evaluate the association between the number of providers on-scene and OHCA outcomes. This was a secondary analysis of adults (18 years old) with non-traumatic OHCA from a 10-site North American prospective cardiac arrest registry (Resuscitation Outcomes Consortium) including a 2005-2011 cohort and a 2011-2015 cohort.