Mild traumatic brain injury among a cohort of rugby union players: predictors of time to injury.

This study reports the time to sustain a mild traumatic brain injury (mTBI) among a cohort of community rugby union players. Demographic and player characteristics were collected and players followed up for between one and three playing seasons. 7% of the cohort sustained an mTBI within 10 h of game time, increasing twofold to 14% within 20 h. The mean time to first mTBI was 8 h with an SD of 6.2 (median 6.8 h; IQR: 2.9-11.7 h). Players reporting a recent history of concussion were 20% more likely to sustain an mTBI after 20 h of game time compared with those with no recent history of concussion. Players were likely to sustain an mTBI in shorter time if they trained for <3 h/week (HR=1.48, p=0.03) or had a body mass index <27 (HR=1.77, p=0.007). The findings highlight modifiable characteristics to reduce the likelihood of shortened time to mTBI.