Does the presence of physician-staffed emergency medical services improve the prognosis in out-of-hospital cardiac arrest? A propensity score matching analysis.

Background: Substantial differences in survival after out-of-hospital cardiac arrest (OHCA) have been observed between countries. These might be attributed to the organization of emergency medical service (EMS) systems, including prehospital physician involvement. However, limited data exist on the physician's role in improving survival after OHCA.

Aims: To compare prehospital and in-hospital outcomes of OHCA patients attended by physician-staffed EMS vs. paramedic-staffed EMS units.

Methods: Among all patients enrolled in the regional, prospective registry of OHCA in southern Poland, we excluded those aged <18 years, with unwitnessed or EMS-witnessed cardiac arrest, without attempted cardiopulmonary resuscitation (CPR), attended by more than one EMS, or with traumatic cardiac arrest. The groups were matched 1:1 using propensity scores for baseline characteristic variables that might influence physician-staffed EMS dispatch.

Results: A total of 812 OHCA cases were included in the current analysis. Among them, 351 patients were attended by physician-staffed EMS. There were no differences in baseline characteristics in the propensity-score matched cohort consisting of 351 pairs. The return of spontaneous circulation (ROSC) was more often achieved in the physician-staffed EMS group (42.7% vs. 33.3%; P = 0.01). The prehospital survival rate was also higher in this group (34.1% vs. 19.2%; P <0.01). However, there were no significant differences in survival rate to discharge between cases treated by physician-staffed and paramedic-staffed EMS (9.7% vs. 7.0%; P = 0.22).

Conclusions: OHCA patients attended by physician-staffed EMS were more likely to have ROSC and survive till hospital admission. However, better prehospital outcomes might not translate into improved in-hospital prognosis in these patients.