Godley 1994.

Methods	Allocation: part randomised within larger study. Design: multi‐centre (6 sites, 4 sites not randomised). Duration: 24 months. Setting: community (6 sites, 4 sites not randomised). Location: Illinois, USA.
Participants	Diagnosis: DSM‐III R major psychiatric and substance abuse/dependence disorder. N = 97 (2 randomised sites). Age: mean ˜ 35 years. Sex: 77 M, 20 F. Ethnicity: white 38%, Hispanic 38%, other 24%. Inclusion criteria: DSM‐III R major psychiatric and substance abuse/dependence disorder.
Interventions	1. Psychosocial intervention: specialised case management services for mentally ill substance abusers (N = 52). 2. Standard care: standard care (N = 45).
Outcomes	No usable data*: Substance use: drug and alcohol questionnaire (unpublished scale). Global state: Area of Difficulty Checklist (unpublished scale), Vocational Outcomes Form (adapted scale), GAF (data not reported). Homelessness: number of state‐operated facility admissions, number of state‐operated facility days, and average length of stay (data skewed).
Notes	Not ITT analysis. *No usable data, only skewed data reported for the 2 randomised sites.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No description of the process.
Allocation concealment (selection bias)	Unclear risk	No details.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Clinician‐/participant‐mediated and participants and personnel not blinded. It is not possible to blind a psychosocial intervention.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not stated if raters were blinded.
Incomplete outcome data (attrition bias) All outcomes	High risk	Lost to follow‐up: 37% (36/97) 1 year, >51% at 18 and 24 months for randomised groups. Insufficient reporting of missing data (numbers and reasons for missing data are reported not for each intervention group).
Selective reporting (reporting bias)	High risk	Results are presented for each site, not combined for each treatment. Combined data from randomised and non‐randomised sites. Unusable.
Other bias	Low risk	No details.