Table 5

Relative risk reduction and numbers-needed-to-treat analyses for overall anterior cruciate ligament injury

ReferenceOverall ACL injury in groupFemale athletes per groupOverall ACL incidence rates*RRR (95% CI)NNT to benefit (NNTB)†,
NNT to harm (NNTH)‡ (95% CI)
Hewett et al
 Control54630.1149.4187 NNTB
 Intervention23660.06(−63.7, 84.4)(58 NNTB to ∞ to 149 NNTH)
Soderman et al
 Control1780.12−403.219 NNTH
 Intervention4620.68(−712.8, -211.6)(70 NNTB to ∞ to 9 NNTH)
Heidt et al
 Control8258NA §23.2139 NNTB
 Intervention142(−498.3, 90.1)(17 NNTB to ∞ to 22 NNTH)
Myklebust et al
 Control299420.1412.6257 NNTB
 Intervention (First only)238550.06(−19.0, 35.9)(52 NNTB to ∞ to 86 NNTH)
Olsen et al
 Control97780.1067.9127 NNTB
 Intervention38080.03(14.4, 88.0)(61 NNTB to ∞ to 1334 NNTH)
Petersen et al
 Control51420.2178.836 NNTB
 Intervention11340.04(−27.4, 96.5)(17 NNTB to ∞ to 170 NNTH)
Gilchrist et al
 Control185830.3473.444 NNTB
 Intervention78520.20(50.0, 85.8)(27 NNTB to 136)
Steffen et al
 Control59470.0829.4644 NNTB
 Intervention410730.06(−46.8, 66.0)(135 NNTB to ∞ to 231 NNTH)
 Control8041910.1443.8120 NNTB
 Intervention4541920.06(28.9, 55.5)(74 NNTB to 316)
  • *Relative incidence rate (per 1000 A*h).

  • †NNT to benefit (NNTB) represents a beneficial preventive effect of the intervention.

  • ‡NNT to harm (NNTH) indicates harmful effect of the intervention. Infinity (∞) means no beneficial or harmful effects.

  • §Exposure information was not available in the original report.