Table 3.
Linear Regression Models Results for Functioning Outcomes at End of Treatment as Predicted from WHO One- and Two-Level Reductions in the Last Month of Treatment, Alcohol Dependence Severity Scores, and their Interaction
| COMBINE (n=1383) | UKATT (n=742) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Outcome: | Outcome: | Outcome: | Outcome: Alcohol-related | Outcome: | Outcome: | Outcome: | Outcome: Alcohol-related | ||
| ALT (IU/L) | GGT (IU/L) | Mental health | Consequences | ALT (IU/L) | GGT (IU/L) | Mental health | Consequences | ||
| Predictors | (DrInC) | (APQ) | |||||||
| B (95% CI) | B (95% CI) | B (95% CI) | B (95% CI) | B (95% CI) | B (95% CI) | B (95% CI) | B (95% CI) | ||
| At least one-level reduction last month of treatment | |||||||||
| 1+-level reduction | −12.75 (−20.56, −4.93), p=.001 | −64.94 (−94.18, −35.69), p<.001 | 9.42 (7.51, 11.33), p<.001 | −26.22 (−30.62, −21.82), p<.001 | −17.88 (−25.28, −10.48), p<.001 | −89.77 (−122.50, −57.04), p<.001 | 9.53 (7.36, 11.73), p<.001 | −10.38 (−11.57, −9.20), p<.001 | |
| Dependence severity | 3.00 (−4.14, 10.15), p=.41 | 26.63 (−10.94, 64.21), p=.17 | −2.77 (−4.93, −0.60), p=.01 | 6.43 (1.75, 11.11), p=.007 | −6.57 (−12.10, −1.03), p=.02 | −31.67 (−69.82, 6.47), p=.10 | −0.68 (−2.16, 0.79), p=.36 | 1.51 (0.39, 2.63), p=.008 | |
| Dependence severity × 1+-level reduction | −2.35 (−9.99, 5.29), p=.55 | −30.19 (−71.54, 11.17), p=.15 | 2.42 (0.01, 4.83), p=.049 | −6.35 (−11.75, −0.94), p=.02 | 4.24 (−0.57, 9.05), p=.08 | 24.34 (−13.64, 62.32), p=.21 | 0.06 (−1.65, 1.76), p=.95 | −0.33 (−1.56, 0.90), p=.60 | |
| At least two-level reduction last month of treatment | |||||||||
| 2+-level reduction | −10.91 (−16.59, −5.24), p<.001 | −49.62 (−70.56, −28.67), p<.001 | 8.16 (6.64, 9.67), p<.001 | −21.34 (−24.26, −18.41), p<.001 | −17.21(−23.37, −11.05), p<.001 | −86.69 (−112.81, −60.57), p<.001 | 9.74 (7.65, 11.82), p<.001 | −10.45 (−11.88, −9.02), p<.001 | |
| Dependence severity | 2.25 (−2.84, 7.35), p=.39 | 14.02 (−6.88, 34.92), p=.19 | −2.61 (−4.01, −1.21), p<.001 | 5.95 (3.02, 8.88), p<.001 | −5.34 (−9.33, −1.36), p=.009 | −27.89 (−60.10, 4.32), p=.09 | −0.52 (−2.21, 1.17), p=.54 | 1.09 (0.05, 2.12), p=.04 | |
| Dependence severity × 2+-level reduction | −1.74 (−7.02, 3.54), p=.52 | −17.80 (−41.89, 5.93), p=.14 | 2.54 (0.93, 4.14), p=.002 | −6.45 (−9.86, −3.04), p<.001 | 2.51 (−2.47, 7.48), p=.32 | 20.82 (−11.06, 52.71), p=.20 | 0.08 (−2.07, 2.24), p=.94 | −0.07 (−1.24, 1.10), p=.91 | |
Note. B (SE)=Unstandardized adjusted regression coefficients (95% CI=95% confidence intervals), which can be interpreted as the decrease in outcomes based on achieving at least a 1- or 2-level reduction, at the average of all covariates (age, sex, initial WHO risk level, initial level of the outcome); ALT=alanine aminotransferase; GGT=γ-glutamyltransferase; IU/L=International Units per Liter. DrInC=Drinker Inventory of Consequences; APQ=Alcohol Problems Questionnaire. The reference group for the one-level reduction was no change or an increase in the WHO risk level from baseline to the last month of treatment, 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 last month of treatment. Negative values indicate an improvement in the outcome variable, except mental health where it indicated a worsening. Positive values indicate a worsening in the variable except mental health where it indicates an improvement. All analyses controlled for age, sex, initial WHO risk level, and initial level of the outcomes.