Table 2.

Power estimation considering 4 steps, 1 cluster in each step, a CAC of 90% and a cluster size of 300 women (coefficient of variation of cluster size 0.60)

Baseline CS rate in Robson Group 1	ICC	Relative reduction
		35%	30%	25%	20%
40%*	0.01	100%	99%	97%	86%
	0.02	100%	99%	92%	76%
	0.05	96%	88%	74%	54%
30%**	0.01	99%	96%	88%	70%
	0.02	97%	91%	78%	58%
	0.05	85%	73%	56%	38%

^*CS at the intervention period: 26%, 28%, 30%, 32%

^**CS at the intervention period: 19.5%, 21%, 22.5%, 24%