RESUMO
BACKGROUND: Out-of-hospital cardiac arrest (OHCA) is associated with a poor prognosis and a highly variable survival rate. Few studies have focused on outcomes in rural and urban groups while also evaluating underlying diseases and prehospital factors for OHCAs. OBJECTIVE: To investigate the relationship between the patient's underlying disease and outcomes of OHCAs in urban areas versus those in rural areas. METHODS: We reviewed the emergency medical service (EMS) database for information on OHCA patients treated between January 2015 and December 2019, and collected data on pre-hospital factors, underlying diseases, and outcomes of OHCAs. Univariate and multivariate logistic regression analyses were used to evaluate the prognostic factors for OHCA. RESULTS: Data from 4225 OHCAs were analysed. EMS response time was shorter and the rate of attendance by EMS paramedics was higher in urban areas (p < 0.001 for both). Urban area was a prognostic factor for >24-h survival (odds ratio [OR] = 1.437, 95% confidence interval [CI]: 1.179-1.761). Age (OR = 0.986, 95% CI: 0.979-0.993). EMS response time (OR = 0.854, 95% CI: 0.811-0.898), cardiac arrest location (OR = 2.187, 95% CI: 1.707-2.795), attendance by paramedics (OR = 1.867, 95% CI: 1.483-2.347), and prehospital defibrillation (OR = 2.771, 95% CI: 2.154-3.556) were independent risk factors for survival to hospital discharge, although the influence of an urban area was not significant (OR = 1.211, 95% CI: 0.918-1.584). CONCLUSIONS: Compared with rural areas, OHCA in urban areas are associated with a higher 24-h survival rate. Shorter EMS response time and a higher probability of being attended by paramedics were noted in urban areas. Although shorter EMS response time, younger age, public location, defibrillation by an automated external defibrillator, and attendance by Emergency Medical Technician-paramedics were associated with a higher rate of survival to hospital discharge, urban area was not an independent prognostic factor for survival to hospital discharge in OHCA patients.