Table I.

Means and SDs of alcohol and reinforcement variables.

	Baseline		1-month
Variable	Mean	SD	Mean	SD	Cohen’s d
Drinks/week (n = 11)	20.91	19.78	11.45	10.84	0.59
No. of HDEs (n = 10)	8.20	9.74	3.70	3.71	0.61
Peak BAC (n = 11)	0.12	0.11	0.06	0.06	0.79
Reinforcement ratio (n = 9)	0.40	0.10	0.35	0.21	0.30

Notes: HDE = past month heavy drinking episodes (5/4 drinks per occasion for men/women); BAC = blood alcohol content; reinforcement ratio is the proportion of total reinforcement derived from substance-related activities and is computed from the ARSS-SUV; one participant did not complete the heavy drinking item at baseline and two participants did not complete the ARSS-SUV correctly and thus had missing reinforcement ratio data.