Epidemiology of concussion in men's elite Rugby-7s (Sevens World Series) and Rugby-15s (Rugby World Cup, Junior World Championship and Rugby Trophy, Pacific Nations Cup and English Premiership)

Objective To determine the incidence, nature and causes of concussions sustained during men's elite professional Rugby-7s and Rugby-15s. Design A prospective cohort study recording injuries classified as a time-loss concussion. Population Players competing in the following tournaments: Rugby 15s—English Premiership (2007/2008 to 2010/2011), Rugby World Cup (2007, 2011), Pacific Nations Cup (2012, 2013), Junior World Championship (2008, 2010–2013), Junior World Rugby Trophy (2008, 2010–2013); Rugby 7s—Sevens World Series (2008/2009, 2010/2011 to 2012/2013). Method The study was implemented according to the international consensus statement for epidemiological studies in rugby union; the main outcome measures included the number, incidence (number of concussions/1000 player-match-hours), mean and median severity (days absence) and cause of concussion. Results The incidence of concussion in Rugby-7s was significantly higher than that in Rugby-15s (risk ratio=1.84; p<0.001). The severity of concussions were significantly higher in Rugby-7s than Rugby-15s (mean—Rugby-7s: 19.2, Rugby-15s: 10.1; median—Rugby 7s: 20, Rugby-15s: 7; p<0.001). The main causes of concussion were tackling (44.1%) in Rugby-7s and collisions (43.6%) in Rugby-15s. Significantly more (risk ratio=1.49; p=0.004) concussed players were removed immediately from the game in Rugby-7s (69.7%) compared to Rugby-15s (46.7%). Conclusions Six actions were identified to improve the management of concussion in rugby: implement a pitch-side concussion assessment protocol; improve compliance with return-to-play protocols; work with referees to review the nature and consequences of collisions; improve players’ tackle technique; investigate the forces involved in tackles and collisions; and evaluate reasons for the higher incidence of concussions in Rugby-7s.