Evaluating an early social communication intervention for young children with Down syndrome (ASCEND): results from a feasibility randomised control trial

Table 4 Sample size scenarios

Standard deviation	Target difference	Standardised effect size	Required participants followed up	Target sample size (assuming 20% loss to follow-up)
*Base case*
231	100	0.43	228	286
*Vary SD*
129	100	0.78	72	90
143		0.70	88	110
154		0.65	102	128
174		0.57	130	164
210		0.48	188	236
270		0.37	310	388
*Vary target difference*
231	80	0.35	354	444
	90	0.39	280	350
	110	0.48	188	236
	120	0.52	158	198

ISSN: 2055-5784