title: Factors associated with quality of bystander CPR: the presence of multiple rescuers and bystander-initiated CPR without instruction.
abstract: OBJECTIVE
  To identify the factors associated with good-quality bystander cardiopulmonary resuscitation (BCPR).
  
  
  METHODS
  Data were prospectively collected from 553 out-of-hospital cardiac arrests (OHCAs) managed with BCPR in the absence of emergency medical technicians (EMT) during 2012. The quality of BCPR was evaluated by EMTs at the scene and was assessed according to the standard recommendations for chest compressions, including proper hand positions, rates and depths.
  
  
  RESULTS
  Good-quality BCPR was more frequently confirmed in OHCAs that occurred in the central/urban region (56.3% [251/446] vs. 39.3% [42/107], p=0.0015), had multiple rescuers (31.8% [142/446] vs. 11.2% [12/107], p<0.0001) and received bystander-initiated BCPR (22.0% [98/446] vs. 5.6% [6/107], p<0.0001). Good-quality BCPR was less frequently performed by family members (46.9% [209/446] vs. 67.3% [72/107], p=0.0001), elderly bystanders (13.5% [60/446] vs. 28.0% [30/107], p=0.0005) and in at-home OHCAs (51.1% [228/446] vs. 72.9% [78/107], p<0.0001). BCPR duration was significantly longer in the good-quality group (median, 8 vs. 6min, p=0.0015). Multiple logistic regression analysis indicated that multiple rescuers (odds ratio=2.8, 95% CI 1.5-5.6), bystander-initiated BCPR (2.7, 1.1-7.3), non-elderly bystanders (1.9, 1.1-3.2), occurrence in the central region (2.1, 1.3-3.3) and duration of BCPR (1.1, 1.0-1.1) were associated with good-quality BCPR. Moreover, good-quality BCPR was initiated earlier after recognition/witness of cardiac arrest compared with poor-quality BCPR (3 vs. 4min, p=0.0052). The rate of neurologically favourable survival at one year was 2.7 and 0% in the good-quality and poor-quality groups, respectively (p=0.1357).
  
  
  CONCLUSIONS
  The presence of multiple rescuers and bystander-initiated CPR are predominantly associated with good-quality BCPR.
authors.affiliation: Department of Medical Science and Technology, Hiroshima International University Japan. Electronic address: y-takei@hs.hirokoku-u.ac.jp.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takei
authors.affiliation: Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine Japan. Electronic address: ntaiki24@yahoo.co.jp.
authors.forename: Taiki
authors.initials: T
authors.lastname: Nishi
authors.affiliation: Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine Japan. Electronic address: h.matsubara@city.kaga.lg.jp.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Matsubara
authors.affiliation: Department of Neurosurgery, Noto General Hospital Japan. Electronic address: hashim@noto-hospital.jp.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hashimoto
authors.affiliation: Department of Emergency Medical Science, Kanazawa University Graduate School of Medicine Japan. Electronic address: hidinaba@med.kanazawa-u.ac.jp.
authors.forename: Hideo
authors.initials: H
authors.lastname: Inaba
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016887:Cardiopulmonary Resuscitation / Q000193:education / Q000592:standards; D017028:Caregivers; D004632:Emergency Medical Services / Q000592:standards; D004634:Emergency Medical Technicians; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality / Q000628:therapy*; D011446:Prospective Studies; D011787:Quality of Health Care
keywords: Bystander CPR; Bystander initiative; Multiple rescuers; Out-of-hospital cardiac arrest