Curtis‐New York 1992.

Methods	Allocation: randomised. Design: single centre. Duration: 14 months. Country: New York, USA. Follow‐up*: range of 18 to 52 months.
Participants	Diagnosis**: not stated, DSM‐III. N = 292. Setting: Harlem Hospital Center (HHC). Age: age 18 to 54 years, mean ± SD 35.9 ± 12.1 yrs (N = 430). Sex: 59% F. Ethnicity: 91% black (understood to be African‐American). History***: i. about to be discharged from hospital, ii. local residents, iii. without a sole diagnosis of substance abuse or organic mental disorder, iv. inpatients for > 7 days, and not eligible for the "Community Support System" programme ‐ that is no psychiatric admission of > 6 months duration/3 admissions of > 10 days within the last 2 years, v. informed consent given.
Interventions	1. ICM: intensive outreach case management from a multidisciplinary team at HHC, which implemented a discharge treatment plan and monitored clinical and social problems. The team did not "assume direct responsibility for care but [...] help[ed] the patient enrol in a day hospital programme, adult mental health clinic, rehabilitation programme, or alcohol treatment programme". Caseload: 1:17. N = 147. 2. Standard care: routine aftercare, within the discharge treatment plan prescribed for each patient by HHC; "most received at least initial treatment form various divisions of the departments of psychiatry within the Health and Hospitals Corporation". N = 145.
Outcomes	Service use: average number of days in hospital per month, admitted to hospital. Death: all causes and suicide. Unable to use ‐ Use of ambulatory services: this outcome is not listed as an outcome of interest for the review. Quality of life: measuring instrument written by trialists for this particular trial and was not published in peer‐reviewed journal (EAF ‐ Evaluation Aftercare Form).
Notes	*Follow‐up period variable, depending on date of participant's entry into the study. **Schizophrenia 38%; alcohol or drug abuse or dependence 39%. ***Mean number of previous admissions > 1. Some more severely ill clients not included in this part of study as they were eligible for "Community Support System" programme group.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised. No further details.
Allocation concealment (selection bias)	Unclear risk	No details.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Primary outcome: clinician/participant mediated ‐ rating ‐ Unclear. Secondary outcomes: some are clinician/participant mediated ‐ rating ‐ Unclear.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Problematic to blind participants and those providing the intervention in studies comparing ICM intervention with standard care.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Service use (rehospitalisations, hospital‐based ambulatory services) and mortality derived from the shared medical billings systems. Blinding not reported.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Missing data are not addressed.
Selective reporting (reporting bias)	Low risk	Listed outcomes are reported completely.
Other bias	Low risk	Funded by public institution (New York City Health and Hospitals Corporation and foundations). No details. No evidence of the presence of other bias.