Weekly alcohol consumption during treatment was assessed in all studies by calendar-based methods using the Form-90[1]. COMBINE and UKATT provided a validity check of self-reported drinking by biological verification via % carbohydrate-deficient transferrin (%CDT) in COMBINE and γ-glutamyl transferase (GGT) in COMBINE and UKATT. Project MATCH provided a validity check of self-reported drinking by corroborating the self-report data with collateral interviews. For all analyses, we created 3 categories of weekly drinking during treatment: abstinent (no drinking during a given week); low risk drinking (1 or more days with less than 4/5 drinks and no heavy drinking days during a given week); and heavy drinking (at least 1 day with 4/5 or more drinks during a given week).
