title: The impact of partial resuscitation attempts on the reported outcomes of out-of-hospital cardiac arrest in Victoria, Australia: implications for Utstein-style outcome reports.
abstract: BACKGROUND
  Success rates from cardiopulmonary resuscitation (CPR) are often quantified by Utstein-style outcome reports in populations who receive an attempted resuscitation. In some cases, evidence of futility is ascertained after a partial resuscitation attempt has been administered, and these cases reduce the overall effectiveness of CPR. We examine the impact of partial resuscitation attempts on the reported outcomes of out-of-hospital cardiac arrest (OHCA) in Victoria, Australia.
  
  
  METHODS
  Between 2002 and 2012, 34,849 adult OHCA cases of presumed cardiac aetiology were included from the Victorian Ambulance Cardiac Arrest Registry. Resuscitation attempts lasting ≤10min in cases which died on scene were defined as a partial resuscitation. We used logistic regression to identify factors associated with a partial resuscitation attempt in the emergency medical service (EMS) treated population. Survival outcomes with and without partial resuscitations were compared across included years.
  
  
  RESULTS
  The proportion of partial resuscitations in the overall EMS treated population increased significantly from 8.6% in 2002 to 18.8% in 2012 (p for trend<0.001), and were largely supported by documented evidence of irreversible death. Partial resuscitations were independently associated with older age, female gender, initial non-shockable rhythm, prolonged downtime, and lower skill level of EMS personnel. Selectively excluding partial resuscitations increased event survival by 7.6% (95% CI 4.1-11.2%), and survival to hospital discharge increased by 3.1% (95% CI 0.5-5.7%) in 2012 (p<0.001 for both).
  
  
  CONCLUSIONS
  In our EMS system, evidence of futility was often identified after the commencement of a partial resuscitation attempt. Excluding these events from OHCA outcome reports may better reflect the overall effectiveness of CPR.
authors.affiliation: Department of Research and Evaluation, Ambulance Victoria, Doncaster, Victoria, Australia; Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Prahran, Victoria, Australia. Electronic address: ziad.nehme@ambulance.vic.gov.au.
authors.forename: Z
authors.initials: Z
authors.lastname: Nehme
authors.affiliation: Department of Research and Evaluation, Ambulance Victoria, Doncaster, Victoria, Australia; Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Prahran, Victoria, Australia.
authors.forename: E
authors.initials: E
authors.lastname: Andrew
authors.affiliation: Department of Research and Evaluation, Ambulance Victoria, Doncaster, Victoria, Australia; Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Prahran, Victoria, Australia; Intensive Care Unit, Alfred Hospital, Prahran, Victoria, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Bernard
authors.affiliation: Department of Research and Evaluation, Ambulance Victoria, Doncaster, Victoria, Australia; Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Prahran, Victoria, Australia; Discipline of Emergency Medicine, School of Primary, Aboriginal and Rural Health Care, University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000628:therapy*; D058028:Research Report; D012189:Retrospective Studies; D016896:Treatment Outcome; D014739:Victoria; D055815:Young Adult
keywords: Cardiac arrest; Cardiopulmonary resuscitation; Cessation of treatment; Emergency medical services; Futile treatment