Table 1

Match incidence rates (injuries/1000 h) in players with a diagnosed concussion and those that did not have a diagnosed concussion, IRRs used to determine effect size

Player groupAll injuriesExposure (hours)Incidence (95% CI)IRR (95% CI)
Players without diagnosed concussion (n=660)139818 50075.6 (71.7 to 79.7)Ref
Players with diagnosed concussion (n=135)
 Postinjury (following return to play)119976122.1 (105.8 to 141.0)1.6* (1.4 to 1.9)
 Pre-injury (before the concussion)6779983.9 (66.0 to 106.6)1.1 (0.8 to 1.5)
  • *Shows significant difference versus the reference group.

  • IRR, Incidence rate ratio; Ref, denotes reference group for IRR calculations.