Table 4

Results of the subgroup analyses (injury proportions for the intervention and control group and results of univariate logistic regression analysis for the effect of study group on the injury risk and the risk ratio of the intervention group)

NInjury proportion (%)Difference (%) (95% CI)OR (95% CI)*Risk ratio (95% CI)
Intervention groupControl groupIntervention groupControl group
Distance running event†‡
 Marathon31730841.341.20.1 (−7.8 to 8.0)0.97 (0.67 to 1.39)1.00 (0.83 to 1.20)
 Half-marathon36734442.238.14.2 (−3.3 to 11.5)1.21 (0.88 to 1.66)1.11 (0.93 to 1.32)
 10/10.55 km43946432.333.8−1.5 (−7.8 to 4.8)1.02 (0.76 to 1.37)0.96 (0.79 to 1.15)
 5/7.5 km736428.828.10.7 (−15.4 to 16.4)1.13 (0.52 to 2.48)1.02 (0.60 to 1.74)
Sex
 Male62362939.238.30.9 (−4.7 to 6.3)1.10 (0.86 to 1.41)1.02 (0.89 to 1.18)
 Female57355335.834.90.9 (−4.8 to 6.6)1.06 (0.81 to 1.38)1.03 (0.88 to 1.20)
Running experience§
 ≤1 year22421136.639.3−2.7 (−12.1 to 6.6)0.90 (0.58 to 1.38)0.93 (0.73 to 1.18)
 >1 year96996437.836.31.5 (−2.9 to 5.8)1.12 (0.92 to 1.36)1.04 (0.93 to 1.17)
Earlier injury¶
 Yes61162743.944.7−0.8 (−6.4 to 4.8)0.92 (0.72 to 1.19)0.98 (0.87 to 1.11)
 No58555530.927.73.2 (−2.2 to 8.6)1.30 (0.99 to 1.70)1.12 (0.93 to 1.34)
  • *Control group is reference.

  • †Running event is missing for 2 participants.

  • ‡The four participants who registered for multiple distances of one running event were assigned to the longest distance they registered for.

  • §Running experience is missing for 10 participants.

  • ¶Running injury in year before INSPIRE trial.