Citation

Delaney JS. Clin. J. Sport. Med. 2012; 22(3): 289-290.

Affiliation

McGill University Health Centre, Montreal, Quebec, Canada.

Copyright

(Copyright © 2012, Canadian Academy of Sport Medicine, Publisher Lippincott Williams and Wilkins)

DOI

10.1097/JSM.0b013e318256e71e

PMID

22544061

Abstract

OBJECTIVE: : To investigate whether mild traumatic brain injuries (mTBI) occur at a particular time in the playing season among community rugby players and whether there are factors that shorten the injury-free period. DESIGN: : Cohort study. Details are included in the previous study. SETTING: : Competitive nonprofessional rugby clubs and private high schools in the Sydney metropolitan area during 2005-2007. PARTICIPANTS: : Male players, 15 to 48 years of age, were recruited from 8 schools and 26 rugby clubs (total n = 3207; mean age, 23 years; 77% trained for 3 hours per week or more). ASSESSMENT OF RISK FACTORS: : The players reported, on short questionnaires, information on demographic, anthropomorphic, and play-related factors (rugby experience, playing positions, and use of protective equipment). They also gave a history of concussions in the previous year. MAIN OUTCOME MEASURES: : The main outcome measure was the time to first mTBI; that is, the total number of hours of game exposure before the player sustained a concussion. An mTBI was defined as a knock to the head that resulted in dizziness, confusion, loss of coordination, and/or a loss of consciousness that required stoppage of play, stoppage of play with the player needing medical attention, or the player needing to leave the field. Players found to be in a different league or with missing or unreliable data were removed from the analysis (final n = 1958). The included players were similar to the excluded players on a wide range of risk factors, but were older in age (23 years vs 22 years), which was adjusted for in the analyses. MAIN RESULTS: The mean game time to first mTBI (10% of players, n = 187) was 8 hours (SD, 6.2 hours; median, 6.8 hours; interquartile range, 2.9-11.7 hours). Of these players, 163 sustained 1 mTBI and 24 sustained from 1 to 4 mTBI. Within 10 hours (just less than the average number of game-hours per player per season), 7% of the cohort had sustained a first mTBI, and within 20 hours (approximate length of 1 season for adults), 14% had a concussion. In survival regression analysis, the proportion of players who remained mTBI-free over time (up to 70 hours of game play) was higher among those who had no recent history of concussion (P < 0.001), had a body mass index (BMI) of ≥27 kg/m (P = 0.003), who trained for ≥3 hours per week (P = 0.012), or who played school rugby (where the game-hours played were fewer) compared with adult rugby (P = 0.033). CONCLUSIONS: : Mild traumatic brain injuries occurred in approximately 7% of players in the first 10 hours of community rugby game play and continued at the same rate through the season. Players who had a recent history of concussion, a lower BMI, trained less, or played adult rugby were most at risk.

Language: en