Cardiac arrest rates upon arrival at the hospital among patients transported by ambulances from the seacoast

Background Seacoasts are generally considered dangerous, and the situation of patients being transported from the coast to hospitals for emergency care has not been fully examined. To clarify the acute health risk associated with the seacoast, we investigated the survival status of patients who arrived at the hospital following transportation from the seacoast by ambulance compared with patients from other locations, and analyzed related factors. Methods All patients who were transported by ambulance to hospitals between 2020 and 2021 in Japan were enrolled in this study. Patients transported from the seacoast were compared with the patients from other locations with respect to the cardiac arrest rate as a survival state. The variables of sex, age, response time, and cause of injury or illness were also compared between the two groups. To adjust for the influence of these variables, we conducted propensity score matching between the two groups and compared the cardiac arrest rates again. Results Of the enrolled patients, 7,003 were from coastal areas, and 9,780,140 were from other locations. Among seacoast patients, 9.1% experienced cardiac arrest upon hospital arrival, whereas 1.6% of patients from other locations experienced cardiac arrest (P < 0.001). In addition, patients from the seacoastal region were more likely to be male, younger, have a longer response time, and have a higher percentage of drowning. Even after adjusting for these factors via using propensity score matching, the cardiac arrest rate still remained higher in the patients from the seacoast (7.3% vs 4.8%, P < 0.001). Conclusions Even if the characteristic factors of patients from the seacoast, including longer response time and a high percentage of drowning were adjusted by propensity matching, the rate of cardiac arrest remained higher in these patients.