Bagøien 2013.

Methods	RCT.
Participants	Patients attending an emergency psychiatric in‐patient service in Norway. 135 patients in trial overall. 7 patients classified as using BZDs; 4 control condition, 3 experimental condition. Mean age 47.5 years (SD = 19.7) for control, 45.7 years (SD = 17.2) experimental. ICD‐10 classification for psychoactive substance use were used for some patients but not all.
Interventions	Intervention group: MI. The intervention consisted of 2 sessions of manual guided MI delivered individually to the patients by a trained therapist. The manual was developed by two MI trainers in co‐operation with the first author of this manuscript. Each session was planned to last 45 minutes. Depending on the patients' length of stay in the hospital, the second session took place on another day or later the same day. In the first session the patients' ambivalence to substance use was explored. Also the severity of the patients' substance use was considered. In the second session the patients' experiences of substance use and prior attempts to change were explored to build intrinsic motivation for change. Actual readiness for change in substance use patterns and commitment to a change plan were focused on. The intervention was delivered in a MI style. If they wanted, patients received information about, and referral to available follow‐up treatment programs for substance use. The interviewer offered a written summary from the 2 sessions to each patient. Control group: TAU. TAU was individualized according to the clinical condition of the patients during the stay and in accordance with general national and international medical standards. It would usually include detoxification, pharmacotherapy and general psychotherapy. Also, treatment would be given for any coexisting non‐substance‐related disorder, including psychiatric disorders. General information about the harmful effects of substances and suggestions regarding treatment for substance use, including possible referral to specialty substance use treatment institutions, would be given. Planning of discharge with referral to out‐patient and primary community health care after discharge usually would be included.
Outcomes	Self‐report substance use at baseline, 3 months, 6 months, 12 months and 24 months. Urinalysis used at baseline but not for follow‐up time points.
Notes	Funding source: St. Olav Universoty Hospital, Trondheim, Norway. Declaration of interest: None.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomisation was performed by a web‐based system developed and administered by the Unit of Applied Clinical Research, Institute of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway. This was a block randomisation, with the block size for all 3 strata set to 10 in each strata group. The randomisation logarithm was programmed in PHP with a My SQL database".
Allocation concealment (selection bias)	Low risk	"The clinicians making the baseline assessments had no information regarding the block size used for randomisation".
Blinding (performance bias and detection bias) All outcomes	Unclear risk	No objective measures used.
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding or incomplete blinding, and the outcome is likely to be influenced by lack of blinding.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No objective measures used.
Blinding of outcome assessor (detection bias) subjective outcomes	High risk	Patients were not blinded to allocation and patients were self‐reporting the data. However if patients were late returning the questionnaire then a nurse blinded to allocation phoned them. "If we did not receive the questionnaire during the following 14 days, nurses from the department, blind to treatment allocation, made telephone calls to ask for patients' reply".
Incomplete outcome data (attrition bias) All outcomes	High risk	Authors reported 46% loss to follow‐up. To partially compensate for this they applied a regression model which was deemed less susceptible to bias under the assumption of missing data.
Selective reporting (reporting bias)	Low risk	The study protocol is not available, but the published reports include all expected outcomes, including those that were pre‐specified in the method section.