Variable | IRR (95% CI) | ||
---|---|---|---|
All injuries* | Injuries with > 7 d of time loss* | Concussions† | |
Bodychecking experience | |||
≤ 2 years | Ref. | Ref. | Ref. |
≥ 3 years | 1.67 (0.97–2.87) | 1.66 (0.99–2.78) | 1.71 (0.85–3.44) |
Level of play | |||
Elite (top 20%) | Ref. | Ref. | Ref. |
Subelite (lower 80%) | 1.60 (1.11–2.31) | 1.56 (1.05–2.31) | 1.62 (1.02–2.56) |
Player weight | 0.99 (0.98–1.00) | 0.99 (0.98–1.01) | 0.99 (0.98–1.01) |
Injury or concussion in previous 12 mo | |||
No | Ref. | Ref. | Ref. |
Yes | 1.43 (1.08–1.88) | 1.35 (0.94–1.93) | 1.40 (0.89–2.20) |
Previous concussion ever | |||
No | Ref. | Ref. | Ref. |
Yes | 1.33 (1.02–1.73) | 1.32 (0.94–1.85) | 1.58 (1.05–2.39) |
Position | |||
Forward | Ref. | Ref. | Ref. |
Defence | 1.19 (0.91–1.56) | 1.19 (0.85–1.66) | 1.30 (0.89–1.91) |
Goalie | 0.69 (0.40–1.17) | 0.81 (0.44–1.51) | 0.94 (0.47–1.89) |
Note: CI = confidence interval, IRR = incidence rate ratio, Ref. = reference.
↵* Incidence rate ratios based on multiple multilevel Poisson regression analysis, offset for exposure game-hours, with 2 random effects, 1 at a team level and 1 at an individual level, and adjusted for covariates (level of play, player weight, injury in the previous year, previous concussion and position).
↵† Incidence rate ratios based on multiple, mixed effects Poisson regression analysis, offset for exposure game-hours, with a random effect at a team level, and adjusted for covariates (level of play, player weight, injury in the previous year, previous concussion and position).