MATCH 1993.

Methods	Multisite RCT (9 clinical research units and a coordinating centre).
Participants	1726 US inpatients and outpatients.
Interventions	Motivational Enhancement Therapy (MET) vs Cognitive Behavioral Therapy (CBT) vs Twelve‐Step Facilitation Therapy (TSF). Not reported how many people were randomised to each condition.
Outcomes	Physiological primary: Gamma‐glutamyl transferase. Non‐physiological primary: Percent days abstinent, drinks per drinking day, drinking consequences, Secondary: None.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomization to treatment was performed using a computerized urn balancing program designed to minimize differences on critical demographic and matching variables".
Allocation concealment (selection bias)	Unclear risk	Randomization process centrally controlled by the coordination centre.
Blinding (performance bias and detection bias) Patients and providers	Low risk	No blinding, but most outcomes were physiological and also used to validate self‐reports, and not likely to be influenced by lack of blinding.
Blinding (performance bias and detection bias) Assessors	Unclear risk	No blinding, but most outcomes were physiological and also used to validate self‐reports, and not likely to be influenced by lack of blinding.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition was less than 10% at the 3, 6, 9, 12, and 15 months follow‐ups in the aftercare and outpatient groups. Balanced. Reasons for 3‐year attrition in the outpatient group given. The authors state that all randomised participants are included in the analyses, but in a results table they included only data for subjects who had non missing values at all three time points.
Selective reporting (reporting bias)	Unclear risk	Primary outcomes measures (PDA and DDD) reported incompletely (only by graphs). Outcome for drinking consequences only reported in tables for 9‐ and 15 months follow‐up.
Other bias	Low risk	Collateral report, laboratory tests (blood and urine) as check on self‐report. Breathalyzer at each assessment point. Inclusion criteria contained no planned involvement for additional treatment during the study period. There were no differences between groups at baseline. No additional sources of bias appear to be present.