Concussion in Ice Hockey-A Cohort Study Across 29 Seasons

Objective: The aim of this study was to analyze the concussion incidence rate ratios across 29 seasons in a Swedish Hockey League team. Design: Cohort study over 29 seasons within one Swedish elite series ice hockey team. Participants: All players who were part of one Swedish elite ice hockey team during the research period gave consent for participation in the study. Independent Variables: Exposure to top-level Swedish ice hockey. Main Outcome Measures: Incidence rate ratio for concussion and rehabilitation periods due to concussion were calculated and analyzed. Results: During the research period, 267 players in total were part of the team. A total of 1638 traumatic injuries were registered, of which 162 were concussions. Incidence rates (IRs) ranged from 0/1000 games during the first season to 118/1000 games for the final recorded season. The incidence rate ratio was 1.06 (confidence interval, 1.03-1.10) for the entire research period. A shift toward longer rehabilitation periods was discovered. Conclusions: This study showed a significant increase of concussion IR and a trend toward longer rehabilitation periods due to concussion. Possible risk factors were discussed. Risk behavior and rehabilitation protocols should be prioritized areas in the research of concussion in ice hockey.