Table 4.

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

Predictor	COMBINE (n=1383)	UKATT (n=742)
	aOR (95% CI)	aOR (95% CI)
Outcome: At least one-level reduction at one-year follow-up
Sex	1.07 (0.84, 1.30), p=.57	0.75 (0.56, 0.94), p=.02
Age	1.00 (0.99, 1.01), p=.88	1.00 (0.99, 1.01), p=.95
WHO risk level at trial entry	1.05 (0.91, 1.19), p=.47	1.09 (0.97, 1.21), p=.14
Dependence severity	1.12 (0.83, 1.40), p=.40	0.89 (0.72, 1.05), p=.19
1+-level reduction in last month of treatment	3.51 (2.73, 4.29), p<.001	2.65 (2.32, 2.98), p<.001
Dependence severity × 1+-level reduction in last month of treatment	0.89 (0.66, 1.13), p=.40	1.09 (0.74, 1.44), p=.59
Outcome: At least two-level reduction at one-year follow-up
Sex	1.04 (0.82. 1.25), p=.74	0.80 (0.57, 1.03), p=.13
Age	1.00 (0.99, 1.01), p=.92	0.99 (0.99, 1.01), p=.70
WHO risk level at trial entry	0.92 (0.82, 1.03), p=.17	1.21 (1.05, 1.38), p=.005
Dependence severity	1.11 (0.93, 1.29), p=.22	1.01 (0.89, 1.14), p=.84
2+-level reduction in last month of treatment	3.23 (2.55, 3.92), p<.001	2.67 (2.42, 2.92), p<.001
Dependence severity × 2+-level reduction in last month of treatment	0.88 (0.72, 1.04), p=.16	0.95 (0.66, 1.23), p=.72

Note. 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.