Connors 2002.

Methods	RCT.
Participants	126 US clients entering outpatient alcoholism treatment.
Interventions	MI (n =40) vs Role induction (n = 37) vs non‐preparatory session control group (n = 36).
Outcomes	Physiological primary: None. Non‐physiological primary: Abstinent days, heavy drinking days. Secondary: Retention in treatment (therapy session attendance).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Clients were randomly assigned to one of three preparatory intervention conditions".
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgment.
Blinding (performance bias and detection bias) Patients and providers	Unclear risk	Blinding of providers was not possible, but participants could have been blinded.
Blinding (performance bias and detection bias) Assessors	Unclear risk	It is not stated whether the assessors were blinded.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	13 (10%) did not provide Timeline Follow‐Back Interview data at the 12 month point. Of these 13, 12 actively withdrew from the study or ceased cooperation with follow‐up efforts and 1 moved and could not be located. We do not know the attrition for the post‐treatment and the 3, 6, and 9 month follow‐ups. Balance between conditions was not stated and ITT was not performed.
Selective reporting (reporting bias)	Low risk	The published report included all expected outcomes based on the study purposes.
Other bias	Low risk	Collateral report to check on self‐report. There were no differences between groups at baseline. No additional sources of bias appear to be present.