Supporting adolescent girls to stay in school, reduce child marriage and reduce entry into sex work as HIV risk prevention in north Karnataka, India: protocol for a cluster randomised controlled trial

Table 3 Number of clusters required in each arm under different assumed conditions

Transition from 7-8th standard				Retention in school				Proportion married before age 15				Proportion having had sexual intercourse before age 15
Control p	% reduction	K	# clusters per arm	Control p	% reduction	K	# clusters per arm	Control p	% reduction	K	# clusters per arm	Control p	% reduction	K	# clusters per arm
17%	30%	0.15	30.4	40%	20%	0.15	28.3	35%	25%	0.15	20.8	35%	25%	0.15	20.8
		0.2	32.7			0.2	33.9			0.2	24.3			0.2	24.3
		0.25	35.6			0.25	41.2			0.25	28.7			0.25	28.7
	33%	0.15	24.9		23%	0.15	21.3		30%	0.15	14.4		30%	0.15	14.4
		0.2	26.7			0.2	25.5			0.2	16.7			0.2	16.7
		0.25	29.1			0.25	30.8			0.25	19.6			0.25	19.6
13%	30%	0.15	40	30%	20%	0.15	38.8	30%	25%	0.15	24.6	30%	25%	0.15	34.1
		0.2	42.3			0.2	44.4			0.2	28			0.2	37.5
		0.25	45.2			0.25	51.7			0.25	32.4			0.25	41.9
	33%	0.15	32.7		23%	0.15	29.1		30%	0.15	16.9		30%	0.15	23.4
		0.2	34.5			0.2	33.3			0.2	19.2			0.2	25.6
		0.25	36.9			0.25	38.6			0.25	22.1			0.25	28.5
9%	35%	0.15	41.7	20%	23%	0.15	44.8	20%	25%	0.15	37.7	20%	25%	0.15	37.7
		0.2	43.3			0.2	48.9			0.2	41.1			0.2	41.1
		0.25	45.4			0.25	54.2			0.25	45.5			0.25	45.5
	40%	0.15	31.3		25%	0.15	37.7		30%	0.15	25.8		30%	0.15	25.8
		0.2	32.4			0.2	41.1			0.2	28			0.2	28
		0.25	33.9			0.25	45.5			0.25	31			0.25	31

This table shows the number of clusters required in each arm to detect a range of potential effect sizes. Conditions where more than 40 clusters would be required per arm are highlighted in bold.

ISSN: 1471-2458