Table 2.

Within-individual Change in Heavy Episodic Drinking (HED) and Alcohol-related Problems (AP) Following Brief Interventions (N = 348)

	Improved (n = 186)			Non-improved (n = 162)
	Mean	t (185)	d	Mean	t (161)	d
From Baseline to 4 mo.
HED	0.44	10.46**	0.77	−0.13	−2.16*	0.17
AP	0.52	9.29**	0.68	0.36	5.19**	0.41
From 4 mo. to 15 mo.
HED	−0.34	−8.27**	0.61	−0.05	−0.95	0.07
AP	−0.26	−5.55**	0.41	−0.25	−3.82**	0.30
From baseline to 15 mo.
HED	0.10	1.80	0.13	−0.18	−2.58*	0.20
AP	0.26	3.94**	0.29	0.11	1.46	0.11

Note. Positive mean changes indicate decreases; negative mean changes indicate increases. Mean = Mean change.

^*p < .05

^**p < .01.

d = Cohen's effect size; calculated by mean change divided by standard deviation.