Influence of the Presence of Other People on Performing Rescue Actions in Emergency Situations　- A Questionnaire Survey.

Background: Because bystander performance of cardiopulmonary resuscitation in out-of-hospital cardiac arrest cases is influenced by the number of rescuers/bystanders, we assessed the relationship between the presence of other people and performance of rescue actions in an actual emergency situation. Methods and Results: A cross-sectional study was performed using data from an anonymous self-administered questionnaire-based survey that included laypersons who had encountered emergency situations during the past 5 years. Based on their responses related to the presence of other people, laypersons were divided into 2 groups: "single-bystander" (absence of others) and "multiple-bystanders" (presence of others). The primary outcome was any rescue action(s) performed by laypersons during an emergency. A total of 1,219 laypersons were eligible for our analysis; 69 (5.7%) encountered emergencies in which others were absent (single-bystander group) and 1,150 (94.3%) encountered emergencies in which others were present (multiple-bystanders group). The proportion of laypersons who performed any rescue actions was 95.7% in the single-bystander group and 73.8% in the multiple-bystanders group. Conclusions: The proportion of laypersons who performed any rescue actions was lower when other people were present compared with when they were absent.