Eack 2015.

Methods	Allocation: randomised. Design: single‐centre. Duration: 18 months. Setting: outpatients. Location: Pittsburgh, PA, USA.
Participants	Diagnosis: Schizophrenia, N = 17 or schizoaffective disorder (n = 14) and 29 (94%) with SCID substance abuse or dependence with moderate to higher addiction severity for cannabis or alcohol on the Addiction Severity Index. N = 31. Age: mean 38 years (range 18‐ 60 years). Sex: 22 M, 9 F. Ethnicity: not reported. Inclusion criteria: patients with schizophrenia and SUD were stable on antipsychotic medication, IQ > 80 and not dependent on cocaine or opioids.
Interventions	1. Psychosocial intervention: routine care plus Cognitive Enhancement Therapy (CET) with individual and 45 group training sessions in social cognition and 60 hours of computer‐assisted training in attention and problem solving and additional psycho‐educational content on substance use. N = 22. 2. Standard care: routine care only, N = 9
Outcomes	Leaving the study early: lost to treatment, lost to evaluation. Substance use: alcohol or cannabis use last 30 days (unable to use analysis due to small participant number). Mental State: BPRS, GAF (unable to use, composite scores only).
Notes	Trial identifier: NCT01292577. Participants received payment for research assessments. Authors have kindly provided further data.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random sequences were generated using R computer software (author note via email)
Allocation concealment (selection bias)	Low risk	Assignments were maintained by an independent data manager and concealed from data collectors and testers (author note via email)
Blinding of participants and personnel (performance bias) All outcomes	High risk	Particpants and providers would be aware of the group allocation. It is not possible to blind a psychosocial intervention.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	All assessments were conducted by trained raters and assessors were blinded to treatment allocation. Substance use was by last 30 days recall so was by self‐report and participants were aware of their allocation
Incomplete outcome data (attrition bias) All outcomes	High risk	Large difference between groups for attrition with CET group = 47% (9/19) and TAU = 20% (1/9). Although, this is reported in the text as not significantly different (P = 0.148).
Selective reporting (reporting bias)	Low risk	NCT01292577. No indication of selective reporting bias.
Other bias	Low risk	Funding by NIH