Adjusted incidence rate ratios for game-related injury outcomes for ice hockey players aged 15–17 years for first-year players only (n = 520)
| Variable | IRR (95% CI) | ||
|---|---|---|---|
| All injuries* | Injuries with > 7 d of time loss† | Concussion† | |
| Bodychecking experience | |||
| ≤ 2 years | Ref. | Ref. | Ref. |
| ≥ 3 years | 1.87 (1.13–3.08) | 1.80 (0.98–3.31) | 2.06 (1.02–4.19) |
| Level of play | |||
| Elite (top 20%) | Ref. | Ref. | Ref. |
| Subelite (lower 80%) | 1.68 (1.08–2.61) | 1.66 (0.97–2.84) | 2.03 (1.16–3.55) |
| Player weight | 1.00 (0.98–1.02) | 1.00 (0.98–1.02) | 1.02 (0.99–1.04) |
| Injury or concussion in previous 12 mo | |||
| No | Ref. | Ref. | Ref. |
| Yes | 1.50 (1.01–2.22) | 1.60 (0.98–2.63) | 1.24 (0.70–2.20) |
| Previous concussion ever | |||
| No | Ref. | Ref. | Ref. |
| Yes | 1.12 (0.78–1.61) | 1.28 (0.82–1.99) | 1.31 (0.77–2.24) |
| Position | |||
| Forward | Ref. | Ref. | Ref. |
| Defence | 0.94 (0.65–1.37) | 0.96 (0.60–1.51) | 0.97 (0.56–1.68) |
| Goalie | 0.63 (0.32–1.25) | 1.04 (0.52–2.08) | 0.74 (0.29–1.89) |
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).