title: Potential association of bystander-patient relationship with bystander response and patient survival in daytime out-of-hospital cardiac arrest.
abstract: OBJECTIVE
  To investigate whether the bystander-patient relationship affects bystander response to out-of-hospital cardiac arrest (OHCA) and patient outcomes depending on the time of day.
  
  
  METHODS
  This population-based observational study in Japan involving 139,265 bystander-witnessed OHCAs (90,426 family members, 10,479 friends/colleagues, and 38,360 others) without prehospital physician involvement was conducted from 2005 to 2009. Factors associated with better bystander response [early emergency call and bystander cardiopulmonary resuscitation (BCPR)] and 1-month neurologically favourable survival were assessed.
  
  
  RESULTS
  The rates of dispatcher-assisted CPR during daytime (7:00-18:59) and nighttime (19:00-6:59) were highest in family members (45.6% and 46.1%, respectively, for family members; 28.7% and 29.2%, respectively, for friends/colleagues; and 28.1% and 25.3%, respectively, for others). However, the BCPR rates were lowest in family members (35.5% and 37.8%, respectively, for family members; 43.7% and 37.8%, respectively, for friends/colleagues; and 59.3% and 50.0%, respectively, for others). Large delays (≥ 5 min) in placing emergency calls and initiating BCPR were most frequent in family members. The overall survival rate was lowest (2.7%) for family members and highest (9.1%) for friends/colleagues during daytime. Logistic regression analysis revealed that the effect of bystander relationship on survival was significant only during daytime [adjusted odds ratios (95% CI) for survival from daytime OHCAs with family as reference were 1.51 (1.36-1.68) for friends/colleagues and 1.23 (1.13-1.34) for others].
  
  
  CONCLUSIONS
  Family members are least likely to perform BCPR and OHCAs witnessed by family members are least likely to survive during daytime. Different strategies are required for family-witnessed OHCAs.
authors.affiliation: Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan; Department of Surgery, Shin Kyoto-Minami Hospital, 94 Goshonouchikita-machi, Shimogyo-ku, Kyoto 600-8861, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Maeda
authors.affiliation: Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Kamikura
authors.affiliation: Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan.
authors.forename: Taiki
authors.initials: T
authors.lastname: Nishi
authors.affiliation: Department of Cardiology, Kanazawa Medical Centre, 1-1 Ishibiki-machi, Kanazawa, Ishikawa 920-8650, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Omi
authors.affiliation: Emergency Medical Centre, Noto General Hospital, a-6-4 Fujihashi-machi, Nanao, Ishikawa 926-0816, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hashimoto
authors.affiliation: Department of Cardiology, Kanazawa Medical Centre, 1-1 Ishibiki-machi, Kanazawa, Ishikawa 920-8650, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Sakagami
authors.affiliation: Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, Ishikawa 920-8641, Japan. Electronic address: hidinaba@med.kanazawa-u.ac.jp.
authors.forename: Hideo
authors.initials: H
authors.lastname: Inaba
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016887:Cardiopulmonary Resuscitation; D004632:Emergency Medical Services; D005190:Family; D005260:Female; D033062:Friends; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality* / Q000628:therapy*; D011446:Prospective Studies; D015996:Survival Rate
keywords: Bystander–patient relationship; Cardiopulmonary resuscitation; Out-of-hospital cardiac arrest; Patient survival; Time of day