Table 2

Univariate Cox regression analyses for all potential injury risk factors. HR are adjusted for clustering within schools.

OverallLeisure time PAPE classesSports
HR (95% CI)p ValueHR (95% CI)p ValueHR (95% CI)p ValueHR (95% CI)p Value
Gender
 Boys10.00410.01310.78510.617
 Girls1.85 (1.22 to 2.79)2.16 (1.18 to 3.80)1.13 (0.47 to 2.71)0.85 (0.44 to 1.62)
Age
 910.17810.74910.92310.007
 101.29 (0.54 to 3.12)1.18 (0.32 to 4.40)0.81 (0.14 to 4.53)1.88 (0.39 to 9.04)
 111.44 (0.61 to 3.44)1.62 (0.45 to 5.85)0.81 (0.15 to 4.47)2.72 (0.49 to 10.5)
 122.36 (0.92 to 6.06)1.64 (0.38 to 7.02)1.27 (0.17 to 9.28)7.17 (1.48 to 34.85)
Ethnicity
 Western10.21210.05310.89910.859
 Non-western0.63 (0.31 to 1.30)0.17 (0.03 to 1.03)1.09 (0.27 to 4.42)0.91 (0.34 to 2.48)
Socioeconomic status
 Low10.36910.08210.63810.209
 Medium0.64 (0.34 to 1.19)0.35 (0.12 to 1.01)0.90 (0.24 to 3.33)1.04 (0.39 to 2.79)
 High0.77 (0.42 to 1.42)0.93 (0.39 to 2.22)0.53 (0.12 to 2.30)0.49 (0.17 to 1.46)
BMI*
 Q110.50110.68910.78610.337
 Q21.27 (0.73 to 2.21)1.21 (0.53 to 2.76)0.86 (0.23 to 3.23)1.51 (0.66 to 3.48)
 Q31.42 (0.80 to 2.52)1.45 (0.62 to 3.38)0.92 (0.24 to 3.48)1.00 (0.40 to 2.51)
 Q40.96 (0.51 to 1.79)0.88 (0.36 to 2.14)1.50 (0.46 to 4.89)0.63 (0.22 to 1.82)
MOPER score
 Low10.43710.60510.93410.352
 Medium0.69 (0.39 to 1.22)0.72 (0.34 to 1.53)1.15 (0.33 to 4.09)1.50 (0.45 to 5.03)
 High0.76 (0.38 to 1.52)0.61 (0.21 to 1.77)0.93 (0.18 to 4.78)2.31 (0.63 to 8.51)
Weekly exposure*
 Q1: <=5.00 h1<0.00110.08210.18110.319
 Q2: 5.01–6.70 h0.20 (0.10 to 0.42)0.79 (0.33 to 1.93)1.25 (0.33 to 4.76)0.64 (0.25 to 1.61)
 Q3: 6.71–9.00 h0.06 (0.03 to 0.14)0.43 (0.17 to 1.09)0.42 (0.08 to 2.34)0.62 (0.25 to 1.52)
 Q4: >=9.01 h0.03 (0.01 to 0.07)0.34 (0.13 to 0.88)2.18 (0.64 to 7.35)0.39 (0.15 to 1.04)
  • * Groups represent age- and gender-specific quartiles sampled from the total population.

  • Significant difference compared with reference category.

  • BMI, body mass index; MOPER, MOPER, motor performance; PA, physical activity; PE, physical education.