Table 3

Extrinsic factors associated with injury incidence: univariate results

FactorN*IRIRR95%CIp Value
Player specific factors
  Under 14/15/16/17/schoolboy28357.40.82(0.57 to 1.20)
  Colts3537.40.82(0.46 to 1.46)
  Senior B/reserve70210.51.20(0.78 to 1.85)
  Senior A109215.41.69(1.15 to 2.49)
  Presidents/social40114.51.60(1.00 to 2.55)
  Other2739.20.99(0.56 to 1.77)
  Front row12669.61.00
  Lock7999.11.00(0.70 to 1.42)
  Loose forward122911.11.15(0.85 to 1.57)
  Inside back11049.51.00(0.72 to 1.39)
  Midfield back62911.41.22(0.85 to 1.74)
  Outside back11529.00.94(0.68 to 1.31)
 Playing out of ‘usual position’0.12
  Out of usual position58512.11.00
  In usual position54759.50.81(0.62 to 1.06)
 Participation in preseason training0.32
 Participation in preseason physical conditioning activities0.49
  No participation28429.11.00
  Low impact activities10013.01.46(0.72 to 2.98)
  Moderate impact activities1788.40.92(0.46 to 1.84)
  High impact activities312610.41.14(0.92 to 1.40)
 Practice attendance during season (in previous week)
  One20388.40.76(0.58 to 0.99)
  More341410.30.92(0.71 to 1.18)
Game specific factors
 Time of season0.01
  June/July27448.90.81(0.68 to 0.96)
  August/September6207.30.70(0.51 to 0.97)
  Rain13379.40.94(0.77 to 1.15)
  No wind36199.41.00
  Windy254210.71.10(0.93 to 1.31)
  Warm274610.51.06(0.90 to 1.26)
 Ground condition0.03
  Muddy231610.01.11(0.93 to 1.33)
  Very hard46813.71.46(1.10 to 1.94)
 Warm-up (min)0.26
  0–148768.10.73(0.36 to 1.51)
  15+520610.20.92(0.47 to 1.83)
 Foul play<0.01
  Yes89817.61.99(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.