Third, we assessed only the presence or absence of the implementation of each type of pre-hospital care. We did not assess the detailed conditions of each type of pre-hospital care, such as time from onset, frequency, dosage or route of epinephrine administration, or type of airway management devices used. Depending on these conditions, the results might be markedly different. In further studies, information regarding the detailed conditions of each type of pre-hospital care will be required.