Study	Reason for exclusion
Banerjee 2007	The participants did not meet inclusion criteria because the majority of the sample had a primary substance other than alcohol (methamphetamine).
Hailemariam 2018	The study design did not meet inclusion criteria because it was a cross‐sectional study.
Lash 2011	The study design did not meet inclusion criteria because it was a literature review.
Lash 2013	The study participants did not meet inclusion criteria because only a subset of participants (33%) had an alcohol use disorder only, and the remaining participants were drug dependent with or without alcohol dependence. The proportion of drug dependent participants who were also alcohol dependent was unclear.
Laudet 2007	The study participants did not meet inclusion criteria, as they were described as all polysubstance dependent and only a small proportion (< 20%) reported alcohol as a 'problem substance'.
Moos 1999	The study participants did not meet inclusion criteria as it was unclear which proportion of the sample had an alcohol use disorder or had alcohol as a primary substance.
Morgan‐Lopez 2013	The study intervention did not meet inclusion criteria, as the treatment interventions did not include AA/TSF.
Mueller 2007	The study design and intervention did not meet inclusion criteria, as it was a correlational study and neither intervention included AA/TSF.
Schilling 2002	The study intervention did not meet inclusion criteria, as neither the standard care intervention nor the comparison intervention (motivational interviewing) included AA/TSF.
Ståhlbrandt 2007	This study participants did not meet inclusion criteria because it was not a study of people with alcohol use disorder (i.e. was a non‐clinical sample, which included non‐drinkers)
Tonigan 2010	The study intervention did not meet inclusion criteria, as it was a moderator study examining social phobia as a moderator of the effect of gender on 12‐step participation and substance use outcomes.
Villanueva 2007	The study design did not meet inclusion criteria, as it was a secondary analysis of only a subset of Project MATCH participants (i.e. was an investigation of racial‐ethnic moderators and not main effects).
Walsh 1991	The study participants did not meet inclusion criteria, because some participants were coerced to participate.

TSF: Twelve‐Step Facilitation
VA: Veteran Affairs