title: The Effect of the "Zero Tolerance for Head Contact" Rule Change on the Risk of Concussions in Youth Ice Hockey Players.
abstract: BACKGROUND
  Ice hockey is a popular winter sport in Canada. Concussions account for the greatest proportion of all injuries in youth ice hockey. In 2011, a policy change enforcing "zero tolerance for head contact" was implemented in all leagues in Canada.
  
  
  OBJECTIVE
  To determine if the risk of game-related concussions and more severe concussions (ie, resulting in >10 days of time loss) and the mechanisms of a concussion differed for Pee Wee class (ages 11-12 years) and Bantam class (ages 13-14 years) players after the 2011 "zero tolerance for head contact" policy change compared with players in similar divisions before the policy change.
  
  
  METHODS
  Cohort study; Level of evidence, 3.
  
  
  METHODS
  The retrospective cohort included Pee Wee (most elite 70%, 2007-2008; n = 891) and Bantam (most elite 30%, 2008-2009; n = 378) players before the rule change and Pee Wee (2011-2012; n = 588) and Bantam (2011-2012; n = 242) players in the same levels of play after the policy change. Suspected concussions were identified by a team designate and referred to a sport medicine physician for diagnosis. Incidence rate ratios (IRRs) were estimated based on multiple Poisson regression analysis, controlling for clustering by team and other important covariates and offset by game-exposure hours. Incidence rates based on the mechanisms of a concussion were estimated based on univariate Poisson regression analysis.
  
  
  RESULTS
  The risk of game-related concussions increased after the head contact rule in Pee Wee (IRR, 1.85; 95% CI, 1.20-2.86) and Bantam (IRR, 2.48; 95% CI, 1.17-5.24) players. The risk of more severe concussions increased after the head contact rule in Pee Wee (IRR, 4.12; 95% CI, 2.00-8.50) and Bantam (IRR, 7.91; 95% CI, 3.13-19.94) players. The rates of concussions due to body checking and direct head contact increased after the rule change.
  
  
  CONCLUSIONS
  The "zero tolerance for head contact" policy change did not reduce the risk of game-related concussions in Pee Wee or Bantam class ice hockey players. Increased concussion awareness and education after the policy change may have contributed to the increased risk of concussions found after the policy change.
authors: Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.
authors: Maciej P
authors: MP
authors: Krolikowski
authors: Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.|Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada.|Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
authors: Amanda M
authors: AM
authors: Black
authors: Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.|Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors: Luz
authors: L
authors: Palacios-Derflingher
authors: Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.
authors: Tracy A
authors: TA
authors: Blake
authors: Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.|Alberta Children's Hospital Research Institute, Calgary, Alberta, Canada.|Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.
authors: Kathryn J
authors: KJ
authors: Schneider
authors: Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.|Community Health Sciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.|Department of Paediatrics, University of Calgary, Calgary, Alberta, Canada.
authors: Carolyn A
authors: CA
authors: Emery
mesh_terms: D000293:Adolescent; D000416:Alberta / Q000453:epidemiology; D001265:Athletic Injuries / Q000453:epidemiology / Q000209:etiology; D001924:Brain Concussion / Q000453:epidemiology* / Q000209:etiology; D002648:Child; D015331:Cohort Studies; D005260:Female; D006688:Hockey / Q000293:injuries* / Q000331:legislation & jurisprudence; D006801:Humans; D015994:Incidence; D008297:Male; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012307:Risk Factors
keywords: child and adolescent; concussion; ice hockey; injury prevention