Kahler 2004.

Methods	RCT.
Participants	48 US patients undergoing inpatient detoxification for alcohol dependence.
Interventions	MET for 12‐step involvement (n= 24) vs brief advice to attend AA (n= 24).
Outcomes	Physiological primary: None. Non‐physiological primary: Percent of days abstinent, drinks per drinking day. Secondary: AA/NA attendance and involvement.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Eight cohorts of 6 participants were run to obtain the desired sample with treatment conditions for each cohort determined randomly."
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgment.
Blinding (performance bias and detection bias) Patients and providers	High risk	No blinding.
Blinding (performance bias and detection bias) Assessors	Low risk	"RAs (research assistants) were blind to treatment assignment of individuals and cohorts."
Incomplete outcome data (attrition bias) All outcomes	Low risk	48 were randomised. Attrition was 4%, 4%, 6%, 6%, 12%, and 12% at 1,2,3,4,5, and 6 months follow‐up, respectively. No reasons for insufficient data reported. No ITT performed.
Selective reporting (reporting bias)	Low risk	The published report included all expected outcomes based on the study hypotheses.
Other bias	Unclear risk	Collateral reports were used. However, because the two treatments were of different length, it is not possible to determine whether treatment intensity rather than treatment content caused the observed effects. There were no differences between groups at baseline.