Incidence and epidemiology of out-of-hospital cardiac arrest in Upper Austria

OBJECTIVE: To determine the incidence and epidemiology of out-of-hospital cardiac arrest (OHCA) with resuscitation attempts by emergency physician teams in Upper Austria. METHODS: This multicenter, retrospective study included all OHCA cases attended by all 22 physician-staffed emergency medical service units operating in Upper Austria between 2017 and 2024. The primary endpoint was the annual incidence of OHCA with resuscitation attempts per 100,000 inhabitants. Secondary endpoints included the proportion of cases in which resuscitation was not attempted, patient demographics, OHCA etiology and OHCA location. RESULTS: During the study period, 15,200 OHCA cases were attended by emergency physician teams. Resuscitation was attempted in 9343 patients (61.5%), while death was pronounced without resuscitation in 5857 (38.5%). The median (interquartile range, IQR) annual incidence of OHCA with resuscitation attempts was 78.9 (76.9-81.9)/100,000 inhabitants. Adults accounted for 98.5% of OHCA cases with 77.8 (76.0-80.5)/100,000 inhabitants/year. Of these 91.9% were due to medical etiologies with 71.1 (69.8-74.5)/100,000 inhabitants/year, while external (mostly traumatic) etiologies accounted for 8.1% (6.3 (5.7-6.8)/100,000 inhabitants/year). Pediatric OHCA constituted 1.5% of all cases with 1.1 (1.1-1.3)/100,000 inhabitants/year and was equally distributed between medical and external causes. CONCLUSION: In this first systematic assessment of OHCA epidemiology in Upper Austria, OHCA with resuscitation attempts by emergency physician teams occurred at a median annual incidence of 78.9 per 100,000 inhabitants. Adult OHCA of medical origin accounted for the vast majority of cases. These findings provide a comprehensive epidemiological overview of OHCA in Upper Austria and highlight the potential value of establishing a prospective, nationwide OHCA registry to facilitate benchmarking, quality improvement initiatives and future outcome analyses.