Table 4:
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 | 3.51 (2.13–5.80) | 3.44 (1.88–6.29) | 3.95 (1.95–8.01) |
| Level of play | |||
| Elite (top 20%) | Ref. | Ref. | Ref. |
| Subelite (lower 80%) | 1.67 (1.08–2.59) | 1.65 (0.97–2.79) | 2.02 (1.16–3.51) |
| 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 (1.00–2.24) | 1.60 (0.97–2.62) | 1.24 (0.70–2.19) |
| Previous concussion ever | |||
| No | Ref. | Ref. | Ref. |
| Yes | 1.11 (0.76–1.61) | 1.27 (0.82–1.97) | 1.30 (0.76–2.22) |
| Position | |||
| Forward | Ref. | Ref. | Ref. |
| Defence | 0.95 (0.65–1.40) | 0.96 (0.61–1.52) | 0.97 (0.56–1.69) |
| Goalie | 0.62 (0.31–1.25) | 1.03 (0.51–2.06) | 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).