Participant equipment information for the prospective cohort and nested case–control analytic approaches
| Variable | Prospective cohort | Nested case–control | |
| Player-seasons (n=5356) | Player concussions (cases; n=490) | Player acute MSK injuries (controls; n=420) | |
| Mouthguard, n (%) | |||
| No use | 1064 (19.9) | 185 (37.8) | 120 (28.6) |
| Yes use | 3871 (72.2) | 251 (51.2) | 234 (55.7) |
| Off-the-shelf type | 2398 (62.0 of users) | 101 (40.2 of users) | 75 (32.1 of users) |
| Dentist-fit type | 1376 (35.6 of users) | 48 (19.1 of users) | 55 (23.5 of users) |
| Missing type | 97 (2.5 of users) | 102 (40.6 of users) | 104 (44.4 of users) |
| Missing use | 421 (7.9) | 54 (11.0) | 66 (15.7) |
| Helmet age, n (%) | |||
| <2 years | 2710 (50.6) | 193 (39.4) | 163 (38.8) |
| ≥2 years | 2021 (37.7) | 125 (25.5) | 94 (22.4) |
| Missing | 625 (11.7) | 172 (35.1) | 163 (38.8) |
| Facemask type, n (%) | |||
| Full wire cage | 4686 (87.5) | 281 (57.3) | 236 (56.2) |
| Full shield/shield-cage combo | 68 (1.3) | 6 (1.2) | 0 (0) |
| Missing | 602 (11.2) | 203 (41.4) | 184 (43.8) |
Equipment (mouthguard use and type, helmet age, facemask type) for the prospective cohort is collected at baseline and at time of injury for the nested case–control approaches.
MSK, musculoskeletal.