Table 1.

Sample characteristics

	VAR (N = 29)	NTX (N = 28)	VAR+NTX (N = 25)	Placebo (N = 27)
Age	34.24 (10.92)	30.50 (8.60)	30.40 (8.71)	38.88 (9.81)*
Education (years)	13.86 (3.31)	13.21 (3.98)	13.76 (3.26)	13.96 (4.00)
Sex (% Male)	65.52%	75.00%	52%	66.67%
Ethnicity (% Caucasian)	33.33%	39.29%	29.17%	53.85%
FTND Score	3.55 (1.86)	3.50 (1.95)	3.76 (1.59)	4.04 (1.99)
Cigarettes per Day	14.08 (4.76)	14.01 (5.25)	14.46 (7.31)	14.13 (5.17)
Drinking Days per Month	22.03 (8.15)	21.71 (7.66)	18.84 (7.98)	20.56 (8.25)
Drinks Per Drinking Day	6.49 (4.48)	6.43 (3.29)	7.20 (3.52)	6.08 (3.32)
Screen CO level (ppm)	0.015 (0.012)	0.014 (0.010)	0.013 (0.007)	0.016 (0.012)
Session CO level (ppm)	0.006 (0.004)	0.007 (0.007)	0.005 (0.003)	0.008 (0.008)

Data are presented as mean (standard deviation) or percentage. The CO level assessed at the screening session (Screen CO) did not have an abstinence requirement, while the CO level assessed at the experimental session (Session CO) was after a 12 hour abstinence requirement.

^*The placebo group was significantly older than both the NTX and NTX + VAR groups (F (3, 104) = 4.57, p < 0.01; Tukey’s HSD p’s ≤ 0.01)