Background In 2013, Hockey Canada introduced an evidence-informed policy change delaying the earliest age of introduction to body checking in hockey until Bantam (ages 13–14) nationwide.

Objective To determine if the risk of injury, including concussions, differs for Pee Wee (11–12 years) ice hockey players in the hockey season following a national policy change disallowing body checking (2013–2014) compared with a season (2011–2012) when body checking was allowed.

Design Historical cohort study.

Setting Ice hockey rinks (Alberta, Canada).

Participants Pee Wee players (all divisions of play) in 2011/12 Alberta prior to the rule change (59 teams, n=883) and 2013/14 following the rule change (73 teams, n=617).

Assessment of Risk Factors Exposure to a Pee Wee league where policy change disallowed body checking.

Main Outcome Measurements Injuries were identified by a safety designate or team therapist if players: 1) required medical attention, 2) were unable to complete the session and/or 3) were unable to participate in sporting activity for one day. Any player with a suspected concussion was referred to a study sport medicine physician.

Results There were 163 game-related injuries [incidence rate (IR)=4.37/1000 game-hours], and 104 concussions (IR=2.79/1000 game-hours) prior to the rule change and 48 injuries (IR=2.16/1000 game-hours) and 24 concussions (IR=1.08/1000 game-hours) after the rule change. Based on a multivariable Poisson regression model adjusting for player size, age, body checking attitudes, previous injury, level of play, and position, accounting for clustering by team, the rate of injury and concussions significantly declined following policy change [IRR=0.50 (95% CI; 0.33 to 0.75)] and [IRR=0.34 (95% CI; 0.21 to 0.56), respectively].

Conclusions Introduction of the 2013 national body checking policy change disallowing body checking in Pee Wee had a significant public health impact resulting in a 50% reduction in injury risk and a 66% reduction in concussion risk in Alberta, Canada.