Table 1.

Effects of social network predictors and propensity stratification on drinking outcomes at study Month 15, aftercare arm

Effect	Percentage of days abstinent			Drinks per drinking day
	F	df	p	F	df	p
Pro-abstainer main effect	3.96	5,15977	.0014	1.52	5,12283	.1794
Pro-abstainer by strata interaction	0.09	1, 1346	.7662	0.02	1,712.49	.8873
Stratification main effect	0.83	4, 37649	.5070	0.69	4, 29724	.6009
Pro-drinker main effect	10.08	5,13001	<.0001	5.22	5,13774	<.0001
Pro-drinker by strata interaction	2.38	1,3326.4	.1229	0.80	1,2407.9	.3708
Stratification main effect	1.83	4,68711	.1200	1.10	4,74775	.3533