Feasibility trial evaluation of a physical activity and screen-viewing course for parents of 6 to 8 year-old children: Teamplay

Table 2 Sample size calculations to detect a 10 minute difference in child weekend day moderate-to-vigorous physical activity between intervention and control groups

SD (mins)	α	β	N required per group	Total N required for analysis	Total N inflated for attrition	Total N rounded and based on 10 participants per course group	Number of intervention groups^$	Number of control groups^$
12	.80	.05	23	46	62.1	80	4	4
12	.80	.01	34	68	91.8	100	5	5
12	.90	.05	31	62	83.7	100	5	5
12	.90	.01	43	86	116.1	120	6	6
17	.80	.05	46	92	124.2	140	7	7
17	.80	.01	68	136	183.6	200	10	10
17	.90	.05	61	122	164.7	180	9	9
17	.90	.01	87	174	234.9	240	12	12
20	.80	.05	63	126	170.1	180	9	9
20	.80	.01	94	188	253.8	260	13	13
20	.90	.05	85	170	229.5	240	12	12
20	.90	.01	120	240	324	340	17	17

ISSN: 1479-5868