Table 6.

Logistic Regression Models Predicting WHO One- and Two-Level Reductions at One-Year Follow-up from WHO One- and Two-Level Reductions in the Last Month of Treatment, Alcohol Dependence Severity Scores, and their Interaction, Excluding Abstainers

Predictor	COMBINE (n=924)	UKATT (n=604)
	aOR (95% CI)	aOR (95% CI)
Outcome: At least one-level reduction at one-year follow-up
Sex	1.04 (0.81, 1.23), p=.75	0.79 (0.60, 0.95), p=.05
Age	0.99 (0.99, 1.01), p=.62	1.00 (0.99, 1.01), p=.60
WHO risk level at trial entry	0.99 (0.84, 1.14), p=.92	1.08 (0.96, 1.21), p=.19
Dependence severity	1.18 (0.91, 1.45), p=.16	0.88 (0.73, 1.03), p=.13
1+-level reduction in last month of treatment	2.80 (2.14, 3.46), p<.001	2.46 (2.08, 2.85), p<.001
Dependence severity × 1+-level reduction in last month of treatment	0.86 (0.64, 1.08), p=.23	1.08 (0.76, 1.40), p=.61
Outcome: At least two-level reduction at one-year follow-up
Sex	1.01 (0.80. 1.22), p=.96	0.82 (0.57, 1.03), p=.20
Age	1.00 (0.99, 1.01), p=.75	0.99 (0.99, 1.01), p=.55
WHO risk level at trial entry	0.91 (0.79, 1.04), p=.19	1.14 (1.01, 1.28), p=.02
Dependence severity	1.13 (0.93, 1.32), p=.18	1.03 (0.89, 1.16), p=.67
2+-level reduction in last month of treatment	2.52 (1.96, 3.07), p<.001	2.66 (2.23, 3.09), p<.001
Dependence severity × 2+-level reduction in last month of treatment	0.87 (0.71, 1.04), p=.16	0.92 (0.66, 1.18), p=.56

Note.

^*p<0.05;

^**p<0.01;

^***p<0.001, aOR (95% CI)=adjusted odds ratios (95% confidence interval). Alcohol dependence severity score was grand mean centered within study. The reference group for the one-level reduction was no change or an increase in the WHO risk level from baseline to the treatment/follow-up months, and the reference group for the two-level reduction was the one-level reduction, no change, or increase in the WHO risk level from baseline to the treatment/follow-up months. All analyses controlled for age, sex, initial WHO risk level, and initial level of the outcomes.