Skip to main content

Table 2 power to detect a specified difference for a fixed sample size

From: CORONIS - International study of caesarean section surgical techniques: the follow-up study

Outcome examples Event rate in 1st group e.g. single layer closure Event rate in 2nd group e.g. double layer closure Absolute risk difference Power available to detect this difference
For all women (number estimated to be ~7,400)
Involuntary infertility 3% 4.5% 1.5% 92%
Subsequent pregnancy 48% 44% 4% 93%
Dyspareunia 19% 16% 3% 92%
For women who have a subsequent pregnancy (number estimated to be ~5,900)
Uterine rupture or dehiscence 4% 5.9% 1.9% 92%
Preterm birth 10% 7.5% 2.5% 93%