Background: Emergency medical centres are located at each area across our country. However, the density of them has regional difference. For example, an urban centre has much more other emergency centres around there. Although there are some multicentre studies about local differences of patients with out-of-hospital cardiac arrest (OHCA), few reports compared them between an urban central area and a suburb city in particular.
Method: Retrospective cohort study was derived from medical records in 2 emergency medical centres (ER); Tokyo Medical and Dental University Medical Hospital (urban centre) and Matsudo City Hospital (suburb). The number of the patients brought to the ERs subsequently to OHCA from 2013 to 2016 were 469 in urban centre and 472 in suburb.
Results: In the urban centre the rate of bystander Cardiopulmonary Resuscitation (CPR) was significantly lower than the suburb (21.3% vs 43.2%, p<0.001), as there was no difference in presence of witnesses. Required time from arrival at on-site and arrival at hospital were significantly longer in the urban centre (28.5 min vs 24.2 min, p<0.001). The rate of ROSC (28.6% vs 43.2%, p<0.001) and the rate of survival on day 28 (3.0% vs 8.5%, p<0.001) were both lower at the urban centre. That was no change in the survival rate after multivariate analysis.
Discussion: Though some reports say bystander CPR has been strengthened in metro areas, our results seem to suggest the tendency of people’s activity that they don’t like interfering with others in metro areas. It may have had some impact with the result that metro area has more buildings, narrower road and more population than suburbs. So, it might take more time for EMS to determine the transportation process to hospitals. Further multicentre studies of the OHCA patients’ characteristics are warranted to evaluate the quality of out-of-hospital resuscitation in many different regions.

Local differences of characteristics of patients with out-of-hospital cardiac arrest