title: A systematic review of the effect of emergency medical service practitioners' experience and exposure to out-of-hospital cardiac arrest on patient survival and procedural performance.
abstract: OBJECTIVE
  Emergency medical service (EMS) practitioners' experience and exposure to out-of-hospital cardiac arrest (OHCA) and advanced life support (ALS) procedures could be an important factor in procedural success and patient survival. We systematically reviewed the literature to examine these associations.
  
  
  METHODS
  We searched for publications using MEDLINE, EMBASE, CINAHL, CENTRAL and Web of Science. We included studies examining any type of EMS practitioner (e.g. paramedics, physicians) and OHCA patients of all ages and aetiologies. Two reviewers independently extracted data.
  
  
  RESULTS
  The search identified 1658 citations, of which 11 observational studies of variable quality were included. The majority of studies did not adjust for important confounding factors and reported across different EMS personnel structures. OHCA survival was not consistently associated with various definitions of career experience in three studies, or with previous OHCA exposure in another study. Endotracheal intubation (ETI) was the only ALS procedure examined. Successful ETI placement was associated with the previous number of ETIs performed in four of five studies, but not career experience in three of four studies. Only one study examined OHCA outcome, and reported an increase in survival to hospital discharge when practitioners had high ETI exposure.
  
  
  CONCLUSIONS
  There is no clear evidence of an association with EMS practitioner career experience or exposure to OHCA cases and ALS procedures, with the exception of exposure to ETI and successful placement. However, most studies in this field had substantial risk of bias. Therefore, further studies are required before any definitive conclusions can be drawn.
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia; Operations Department, Ambulance Victoria, Victoria, Australia. Electronic address: Kylie.dyson@monash.edu.
authors.forename: Kylie
authors.initials: K
authors.lastname: Dyson
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.
authors.forename: Janet
authors.initials: J
authors.lastname: Bray
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia; Research and Evaluation Department, Ambulance Victoria, Melbourne, Australia; Discipline of Emergency Medicine, University of Western Australia, Perth, Australia.
authors.forename: Karen
authors.initials: K
authors.lastname: Smith
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia; Intensive Care Unit, Alfred Hospital, Melbourne, Australia; Medical Advisor, Ambulance Victoria, Victoria, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Bernard
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia; Discipline of Emergency Medicine, University of Western Australia, Perth, Australia; Faculty of Health Sciences, Curtin University, Perth, Australia.
authors.forename: Judith
authors.initials: J
authors.lastname: Finn
mesh_terms: D002983:Clinical Competence; D004632:Emergency Medical Services / Q000592:standards*; D006801:Humans; D007442:Intubation, Intratracheal; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality* / Q000628:therapy*; D015996:Survival Rate
keywords: Clinical competence; Endotracheal intubation; Experience; Exposure; Out-of-hospital cardiac arrest; Systematic review