Table 4.

Power calculations for the Counselling for Alcohol Problems trial on available sample sizes for sub-group analyses

Sub-group	Outcome	Sample size	Power	Effect size
Harmful drinking and alcohol dependence	Mean standard ethanol content consumed in past two weeks	638	0.50	99%
			0.40	92%
			0.33	80%
			0.40	63%
			0.33	48%
Alcohol dependence	Mean standard ethanol content consumed in past two weeks	238	0.50	86%
			0.40	69%