title: Bystander Intervention Prior to The Arrival of Emergency Medical Services: Comparing Assistance across Types of Medical Emergencies.
abstract: To determine the situational circumstances associated with bystander interventions to render aid during a medical emergency.
  
  
  
  This study examined 16.2 million Emergency Medical Service (EMS) events contained within the National Emergency Medical Services Information System. The records of patients following a 9-1-1 call for emergency medical assistance were analyzed using logistic regression to determine what factors influenced bystander interventions. The dependent variable of the model was whether or not a bystander intervened.
  
  
  
  EMS providers recorded bystander assistance 11% of the time. The logistic regression model correctly predicted bystander intervention occurrence 71.4% of the time. Bystanders were more likely to intervene when the patient was male (aOR = 1.12, 95% CI = 1.12-1.3) and if the patient was older (progressive aOR = 1.10, 1.46 age group 20-29 through age group 60-99). Bystanders were less likely to intervene in rural areas compared to urban areas (aOR = 0.58, 95% CI = 0.58-0.59). The highest likelihood of bystander intervention occurred in a residential institution (aOR = 1.86, 95% CI = 1.85-1.86) and the lowest occurred on a street or a highway (aOR = 0.96, 95% CI = 0.95-0.96). Using death as a reference group, bystanders were most likely to intervene when the patient had cardiac distress/chest pain (aOR = 11.38, 95% CI = 10.93-11.86), followed by allergic reaction (aOR = 7.63, 95% CI = 7.30-7.99), smoke inhalation (aOR = 6.65, 95% CI = 5.98-7.39), and respiration arrest/distress (aOR = 6.43, 95% CI = 6.17-6.70). A traumatic injury was the most commonly recorded known event, and it was also associated with a relatively high level of bystander intervention (aOR = 5.81, 95% CI = 5.58-6.05). The type of injury/illness that prompted the lowest likelihood of bystander assistance was Sexual Assault/Rape (aOR = 1.57, 95% CI = 1.32-1.84) followed by behavioral/psychiatric disorder (aOR = 1.64, 95% CI = 1.57-1.71).
  
  
  
  Bystander intervention varies greatly on situational factors and the type of medical emergency. A higher risk of patient death is likely to prompt bystander action. These novel study results can lead to more effective first aid training programs.
  
  
  
  bystander; EMS; rural; cardiac distress; trauma.
authors.forename: Mark
authors.initials: M
authors.lastname: Faul
authors.forename: Shelley N
authors.initials: SN
authors.lastname: Aikman
authors.forename: Scott M
authors.initials: SM
authors.lastname: Sasser
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004632:Emergency Medical Services; D005260:Female; D006379:Helping Behavior; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D055815:Young Adult