Rosenblum 2014.

Methods	Allocation: randomised. Design: multiple sites. Duration: 3 and 6 months. Setting: outpatient and residential. Location: Grand Rapids, MI and New York, NY, USA.
Participants	Diagnosis: serious mental illness (major depression, bipolar disorder, N = 97 and schizophrenia, N = 59) and lifetime history of substance misuse determined by Modified Simple Screening instrument for Substance Abuse. N = 203. Age: 42 years. Sex: 138 M, 65 F. Ethnicity: Hispanic (13%), Black (32%) white (52%), other (5%). Inclusion criteria: Those not meeting current misuse (alcohol > 4 drinks per day or illicit use last 90 days) were excluded.
Interventions	1. Psychosocial intervention: peer‐supported 12‐step self‐help program called Double Trouble in Recovery (DTR), comprising one group meeting per week with a peer facilitator to help develop new skills and coping behaviours, N = 113. 2. Standard care: TAU, received standard residential or day patient treatment and asked not to attend DTR meetings until after follow‐up interview, N = 163.
Outcomes	Leaving the study early: lost to treatment, lost to evaluation. Substance use: number of day any alcohol or drug use past 30 days. Mental State: (QoL unable to use; not standard instrument). Medication Adherence (MARS).
Notes	Trial identifier: NCT01333280 139 excluded after randomisation as they did not meet recent substance misuse criteria. Primary psychiatric diagnoses not reported. Attendees received $30 for baseline interview, $5 per meeting attended and $50‐100 for follow‐up interviews. Funded by NIDA. One author is director of NGO that receives sales from distribution of DTR material.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random numbers table using block randomisation. However, within the 2 regions participants in the two groups differed at baseline on PTSD and bipolar diagnoses. [this issue is addressed in the new ROB2.0 as if randomisation was done appropriately but did not create 2 identical groups then it may indicate that the sequence was not successful (or could be a chance finding)]
Allocation concealment (selection bias)	Low risk	Allocation concealment was by sealed envelopes (assumed to be consecutively numbered and opaque)
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants and providers were aware of their group allocation. It is not possible to blind a psychosocial intervention.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The outcome of substance use was by self‐report but was validated by saliva testing
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition was 20% in the DTR group and 22% in the control condition with no significant difference between groups. We judged this to be low risk
Selective reporting (reporting bias)	Low risk	NCT01333280. No indication of selective reporting.
Other bias	Low risk	NIDA funding