title: What strategies can be used to effectively reduce the risk of concussion in sport? A systematic review.
abstract: OBJECTIVE
  To examine the effectiveness of concussion prevention strategies in reducing concussion risk in sport.
  
  
  METHODS
  Systematic review according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines.
  
  
  METHODS
  Eleven electronic databases searched and hand-search of references from selected studies.
  
  
  METHODS
  The following were the study inclusion criteria: (1) contained original human research data; (2) investigated an outcome of concussion or head impact; (3) evaluated a concussion prevention intervention; (4) included sport participants; (5) analytical study designand (6) peer-reviewed. The following were the exclusion criteria: (1) review articles, case series or case studies and (2) not in English.
  
  
  RESULTS
  The studies selected (n=48) provided evidence related to protective gear (helmets, headgear, mouthguards) (n=25), policy and rule changes (n=13) and other interventions (training, education, facilities) (n=10). Meta-analyses demonstrate a combined effect of a 70% reduction (incidence rate ratio (IRR)=0.3 (95% CI: 0.22 to 0.41)) in concussion risk in youth ice hockey leagues where policy disallows body checking, and the point estimate (IRR=0.8 (95% CI: 0.6 to 1.1)) suggests a protective effect of mouthguards in contact and collision sport (basketball, ice hockey, rugby).
  
  
  CONCLUSIONS
  Highlights include a protective effect of helmets in skiing/snowboarding and the effectiveness of policy eliminating body checking in youth ice hockey. Future research should examine mouthguards in contact sport, football helmet padding, helmet fit in collision sport, policy limiting contact practice in youth football, rule enforcement to reduce head contact in ice hockey and soccer, ice surface size and board/glass flexibility in ice hockey and training strategies targeting intrinsic risk factors (eg, visual training).
  
  
  BACKGROUND
  PROSPERO 2016:CRD42016039162.
authors.affiliation: Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Alberta, Canada.
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Emery
authors.affiliation: Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Alberta, Canada.
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Black
authors.affiliation: Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Alberta, Canada.
authors.forename: Ash
authors.initials: A
authors.lastname: Kolstad
authors.affiliation: Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Alberta, Canada.
authors.forename: German
authors.initials: G
authors.lastname: Martinez
authors.affiliation: Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Alberta, Canada.
authors.forename: Alberto
authors.initials: A
authors.lastname: Nettel-Aguirre
authors.affiliation: Department of Orthopaedic Surgery, Oslo University Hospital and Faculty of Medicine, University of Oslo, Oslo, Norway.|Oslo Sports Trauma Research Center, Oslo, Norway.|Medical and Scientific Department, International Olympic Committee (IOC), Lausanne, Switzerland.
authors.forename: Lars
authors.initials: L
authors.lastname: Engebretsen
authors.affiliation: Division of Neurosurgery, University of Toronto, Ontario, Canada.|Concussion Management Program Athletic Edge Sports Medicine, Ontario, Canada.
authors.forename: Karen
authors.initials: K
authors.lastname: Johnston
authors.affiliation: Carleton University Sport Medicine Centre, Ontario, Canada.|Department of Family Medicine, University of Ottawa, Ontario, Canada.|International Paralympic Committee Medical Committee.
authors.forename: James
authors.initials: J
authors.lastname: Kissick
authors.affiliation: Perry Maddocks Trollope Lawyers.
authors.forename: David
authors.initials: D
authors.lastname: Maddocks
authors.affiliation: Canadian Concussion Centre, Toronto Western Hospital, University Health Network, Ontario, Canada.|Division of Neurosurgery, Department of Surgery, University of Toronto, Ontario, Canada.
authors.forename: Charles
authors.initials: C
authors.lastname: Tator
authors.affiliation: Ottawa Sport Medicine Centre, Ontario, Canada.|International Ice Hockey Federation.|IOC Medical Commission Games Group.
authors.forename: Mark
authors.initials: M
authors.lastname: Aubry
authors.affiliation: Department of Neurology, University of Zurich, Zurich, Switzerland.|Schulthess Clinic Zurich.
authors.forename: Jiří
authors.initials: J
authors.lastname: Dvořák
authors.affiliation: Department of Neurosurgery, Tokushima University Hospital, Tokushima, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Nagahiro
authors.affiliation: Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Alberta, Canada.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Schneider
mesh_terms: D056352:Athletes; D001265:Athletic Injuries / Q000517:prevention & control*; D001490:Basketball / Q000293:injuries; D001924:Brain Concussion / Q000517:prevention & control*; D005538:Football / Q000293:injuries; D006260:Head Protective Devices; D006688:Hockey / Q000293:injuries; D006801:Humans; D009064:Mouth Protectors; D040242:Risk Reduction Behavior; D012865:Skiing / Q000293:injuries; D012916:Soccer / Q000293:injuries
keywords: concussion; prevention; sport Injury