Table 5

SSI analysis by ‘ITT’ assuming (1) all and (2) none of the participants violating protocol or lost to follow-up would have developed SSI

Antibiotic ProphylaxisControl groupP valuesAbsolute risk reduction95% CIRelative risk reduction (%)NNTB (95% CI)
Analysis by ITT: assuming all the participants violating protocol or lost to follow-up would have developed SSI
n=77n=77
No of SSIn=1n=8
Incidence rate of SSI1.3%10.4%P=0.034*9.1%1.8 to 16.487.511.0 (6.1 to 55.6)
Analysis by ITT: assuming none of  the participants violating protocol or lost to follow-up would have developed SSI
n=77n=77
No of SSIn=5n=16
Incidence rate of SSI6.5%20.8%P=0.017*14.3%3.7 to 24.968.87.0 (4.0 to 27.0)
  • *P values are results of Fisher’s exact test.

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