Hsu YC, Wu WT, Huang JB, et al. - The relationship between the patient's underlying disease and outcomes of out-of-hospital cardiac arrest (OHCA) in urban areas vs those in rural areas was investigated via analyzing data from 4,225 OHCAs retrieved from the emergency medical service (EMS) database. Findings revealed a higher 24-h survival rate in correlation with OHCA in urban areas vs rural areas. Urban areas had shorter EMS response time and a higher probability of being attended by paramedics. Although a higher rate of survival to hospital discharge was observed in correlation with shorter EMS response time, younger age, public location, defibrillation by an automated external defibrillator, and attendance by Emergency Medical Technician-paramedics, urban area did not seem to be an independent prognostic factor for survival to hospital discharge in OHCA patients.