Antibiotic Prophylaxis | Control group | P values | Absolute risk reduction | 95% CI | Relative risk reduction (%) | NNTB (95% CI) | |

Analysis of available cases | |||||||

n=73 | n=69 | ||||||

No of SSI | n=1 | n=8 | |||||

Incidence rate of SSI | 1.4% | 11.6% | P=0.015* | 10.2% | 2.2 to 18.2 | 87.9 | 9.8 (5.5 to 45.5) |

Analysis of available cases stratified by sex | |||||||

Male | n=33 | n=44 | |||||

Incidence rate of SSI | 0% (n=0) | 15.9% (n=7) | P=0.018* | 15.9% | 5.2 to 26.6 | 100 | 6.3 (3.8 to 19.2) |

Female | n=40 | n=25 | |||||

Incidence rate of SSI | 2.5% (n=1) | 4.0% (n=1) | P=1.0* | 1.5% | −7.6 to 10.6 | 37.5 | 66.7 (NNTH 13.2 to infinity to NNTB 9.4) |

*P values are results of Fisher’s exact test.

NNTB, number needed to treat for benefit; NNTH, number needed to treat for harm; SSI, surgical site infection.