Bystander-witnessed cardiopulmonary resuscitation by nonfamily is associated with neurologically favorable survival after out-of-hospital cardiac arrest in Miyazaki City District

Background Bystander intervention in cases of out-of-hospital cardiac arrest (OHCA) is a key factor in bridging the gap between the event and the arrival of emergency health services at the site. This study investigated the implementation rate of bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) and 1-month survival after OHCA in Miyazaki prefecture and Miyazaki city district as well as compared them with those of eight prefectures in the Kyushu-Okinawa region in Japan. In addition, we analyzed prehospital factors associated with survival outcomes in Miyazaki city district. Methods We used data from an annual report released by the Fire and Disaster Management Agency of Japan (n = 627,982) and the Utstein reporting database in Miyazaki city district (n = 1,686) from 2015 to 2019. Result Despite having the highest rate of bystander CPR (20.8%), the 1-month survival rate (15.7%) of witnessed OHCA cases of cardiac causes in Miyazaki city district was comparable with that in the eight prefectures between 2015 and 2019. However, rates of survival (10.7%) in Miyazaki prefecture were lower than those in other prefectures. In 1,686 patients with OHCA (74 ± 18 years old, 59% male) from the Utstein reporting database identical to the 5-year study period in Miyazaki city district, binary logistic regression analysis demonstrated that age of the recipient [odds ratio (OR) 0.979, 95% confidential interval (CI) 0.964–0.993, p = 0.004)], witness of the arrest event (OR 7.501, 95% CI 3.229–17.428, p < 0.001), AED implementation (OR 14.852, 95% CI 4.226–52.201, p < 0.001), and return of spontaneous circulation (ROSC) before transport (OR 31.070, 95% CI 16.585–58.208, p < 0.001) predicted the 1-month survival with favorable neurological outcomes. In addition, chest compression at a public place (p < 0.001) and by nonfamily members (p < 0.001) were associated with favorable outcomes (p = 0.015). Conclusions We found differences in 1-month survival rates after OHCA in the Kyushu-Okinawa region of Japan. Our results suggest that on-field ROSC with defibrillation performed by nonfamily bystanders who witnessed the event determines 1-month neurological outcomes after OHCA in Miyazaki city district. Continued education of citizens on CPR techniques and better access to AED devices may improve outcomes.