Factor | N* | IR | IRR | 95%CI | p Value† |
---|---|---|---|---|---|
Player specific factors | |||||
Grade | <0.01 | ||||
Under 14/15/16/17/schoolboy | 2835 | 7.4 | 0.82 | (0.57 to 1.20) | |
Under18/19 | 534 | 9.4 | 1.00 | ||
Colts | 353 | 7.4 | 0.82 | (0.46 to 1.46) | |
Senior B/reserve | 702 | 10.5 | 1.20 | (0.78 to 1.85) | |
Senior A | 1092 | 15.4 | 1.69 | (1.15 to 2.49) | |
Presidents/social | 401 | 14.5 | 1.60 | (1.00 to 2.55) | |
Other | 273 | 9.2 | 0.99 | (0.56 to 1.77) | |
Position‡ | 0.65 | ||||
Front row | 1266 | 9.6 | 1.00 | ||
Lock | 799 | 9.1 | 1.00 | (0.70 to 1.42) | |
Loose forward | 1229 | 11.1 | 1.15 | (0.85 to 1.57) | |
Inside back | 1104 | 9.5 | 1.00 | (0.72 to 1.39) | |
Midfield back | 629 | 11.4 | 1.22 | (0.85 to 1.74) | |
Outside back | 1152 | 9.0 | 0.94 | (0.68 to 1.31) | |
Playing out of ‘usual position’ | 0.12 | ||||
Out of usual position | 585 | 12.1 | 1.00 | ||
In usual position | 5475 | 9.5 | 0.81 | (0.62 to 1.06) | |
Participation in preseason training | 0.32 | ||||
No | 1662 | 9.1 | 1.00 | ||
Yes | 4594 | 10.0 | 1.13 | (0.89-1.43) | |
Participation in preseason physical conditioning activities | 0.49 | ||||
No participation | 2842 | 9.1 | 1.00 | ||
Low impact activities | 100 | 13.0 | 1.46 | (0.72 to 2.98) | |
Moderate impact activities | 178 | 8.4 | 0.92 | (0.46 to 1.84) | |
High impact activities | 3126 | 10.4 | 1.14 | (0.92 to 1.40) | |
Practice attendance during season (in previous week) | |||||
None | 811 | 11.5 | 1.00 | 0.08 | |
One | 2038 | 8.4 | 0.76 | (0.58 to 0.99) | |
More | 3414 | 10.3 | 0.92 | (0.71 to 1.18) | |
Game specific factors | |||||
Time of season | 0.01 | ||||
March/April/May | 2899 | 11.3 | 1.00 | ||
June/July | 2744 | 8.9 | 0.81 | (0.68 to 0.96) | |
August/September | 620 | 7.3 | 0.70 | (0.51 to 0.97) | |
Rain | 0.57 | ||||
Dry | 4823 | 10.0 | 1.00 | ||
Rain | 1337 | 9.4 | 0.94 | (0.77 to 1.15) | |
Wind | 0.25 | ||||
No wind | 3619 | 9.4 | 1.00 | ||
Windy | 2542 | 10.7 | 1.10 | (0.93 to 1.31) | |
Temperature | 0.47 | ||||
Cold | 3397 | 9.4 | 1.00 | ||
Warm | 2746 | 10.5 | 1.06 | (0.90 to 1.26) | |
Ground condition | 0.03 | ||||
Firm | 3379 | 9.4 | 1.00 | ||
Muddy | 2316 | 10.0 | 1.11 | (0.93 to 1.33) | |
Very hard | 468 | 13.7 | 1.46 | (1.10 to 1.94) | |
Warm-up (min) | 0.26 | ||||
None | 84 | 11.9 | 1.00 | ||
0–14 | 876 | 8.1 | 0.73 | (0.36 to 1.51) | |
15+ | 5206 | 10.2 | 0.92 | (0.47 to 1.83) | |
Foul play | <0.01 | ||||
No | 5259 | 8.6 | 1.00 | ||
Yes | 898 | 17.6 | 1.99 | (1.64 to 2.41) |
↵* Number of player games.
↵† p Value for the overall significance of the factor.
↵‡ Playing position groups (position names as specified by International Rugby Board Regulations 14.1): front row (loose head prop, hooker, tight head prop); locks (left lock, right lock); loose forward (left flanker, right flanker, number eight); inside back (scrum half, fly half); midfield backs (left centre, right centre); outside backs (left wing, right wing, full back).
IR, incidence rate; IRR, injury rate ratio.