Descriptive statistics for all risk factors (Pee Wee cohort 2007–2008 and Bantam cohort 2008–2009 season)
| Pee Wee | Bantam | |||
|---|---|---|---|---|
| Alberta (n = 1091) | Quebec (n = 1042) | Alberta (n = 990) | Quebec (n = 976) | |
| Per cent wins, mean (SD) | 46.50 (14.77) | 45.61 (17.36) | 46.30 (18.12) | 46.15 (20.95) |
| Penalty minutes per game, mean (SD) | 8.21 (3.66) | 7.79 (2.30) | 12.31 (4.59) | 11.30 (2.96) |
| Weight, mean (SD) | 43.18 (8.39) | 44.35 (9.04) | 57.60 (10.61) | 59.89 (10.03) |
| Level of play* | ||||
| Upper, n (%) | 413 (37.86) | 390 (37.43) | 374 (37.78) | 308 (31.56) |
| Lower, n (%) | 687 (62.14) | 652 (62.57) | 616 (62.22) | 668 (68.44) |
| Year of play in Pee Wee or Bantam | ||||
| First year, n (%) | 484 (44.36) | 428 (41.07) | 417 (42.12) | 322 (32.99) |
| Second year, n (%) | 596 (54.63) | 590 (56.62) | 556 (56.16) | 642 (65.78) |
| Missing, n (%) | 11 (1.01) | 24 (2.30) | 17 (1.72) | 12 (1.23) |
| Previous injury (1 year) | ||||
| Yes, n (%) | 213 (19.52) | 167 (16.03) | 339 (34.24) | 295 (30.23) |
| No, n (%) | 849 (77.82) | 870 (83.49) | 640 (64.65) | 672 (68.85) |
| Missing | 29 (2.66) | 5 (0.48) | 11 (1.11) | 9 (0.92) |
| Previous concussion (lifetime) | ||||
| Yes, n (%) | 196 (17.97) | 130 (12.48) | 287 (28.99) | 164 (16.80) |
| No, n (%) | 866 (79.38) | 903 (86.66) | 679 (68.59) | 798 (81.76) |
| Missing, n (%) | 29 (2.66) | 9 (0.86) | 24 (2.42) | 14 (1.43) |
| Position | ||||
| Forward, n (%) | 614 (56.28) | 581 (55.76) | 553 (55.86) | 526 (53.89) |
| Defense, n (%) | 328 (30.06) | 333 (31.96) | 312 (31.52) | 329 (33.71) |
| Goalie, n (%) | 131 (12.01) | 113 (10.84) | 109 (11.01) | 114 (11.68) |
| Missing, n (%) | 18 (1.65) | 15 (1.44) | 16 (1.62) | 7 (0.72) |
↵* Level of play was defined within age group. In Pee Wee, the cohort included only the upper 60% of divisions of play overall; thus the study's upper level refers to top 20% and lower level referred to mid-40%. In Bantam, the cohort included only the upper 30% of divisions of play overall; thus the study's upper level includes the top 10% and lower level includes the next 20%.