Stein 2009.

Methods	RCT.
Participants	198 persons who used cocaine at least weekly and who were not in treatment. USA.
Interventions	4‐session motivational intervention (n= 97) or an assessment only control group (n= 101). Both groups received a written handout list of treatment resources. Each session lasted 20 to 40 minutes.
Outcomes	Physiological primary: None. Non‐physiological primary: Any reduction in cocaine use, more than 50% reduction, and abstinence. Secondary: Treatment attendance (inpatient therapy, attended NA or CA, any drug treatment). Follow‐up at 6 months.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomization and concealment were overseen by the study methodologist."
Allocation concealment (selection bias)	Unclear risk	"Randomization and concealment were overseen by the study methodologist."
Blinding (performance bias and detection bias) Patients and providers	High risk	No blinding.
Blinding (performance bias and detection bias) Assessors	Low risk	"Follow‐up interviews were performed by research staff blinded to study conditions."
Incomplete outcome data (attrition bias) All outcomes	Low risk	ITT performed. Attrition was 19% at 6 months. Reasons not stated.
Selective reporting (reporting bias)	Low risk	The published report included all expected outcomes based on the study hypotheses.
Other bias	Unclear risk	Only self‐reported outcomes. There were no differences between groups at baseline.