Study title	Intervention name	Intervention description	Control	Scattered versus congregate	Intervention setting and time	Typology
Appel (2012)	Keeping Home project" "Housing First approach	Keeping Home uses the Housing First approach to address the needs of homeless, mentally ill substance abusers. Specifically, Keeping Home secures market‐rate, scattered site apartments for seriously mentally ill methadone maintenance treatment patients and then uses assertive community treatment to address patients service needs	Usual treatment: available housing and support services	Scattered site	New York City, USA. Between March 2005 and March 2007	High unconditional
Brown (2016)	Housing First	Held at a 75‐unit single‐site HOUSING FIRST program. Residents were not required to abstain from substance use, nor are they required to participate in mental health or substance abuse treatment. However, staff provides assertive engagement to encourage participation. Participants in the HOUSING FIRST program received a breadth of intensive, consumer‐driven support services based on personal need and interest along with housing	Usual treatment: comparison group participants received usual care, comprising access to a variety of supports, including outpatient mental health and/or substance abuse treatment, sobering services, shelter, and/or other supportive housing programs	Congregate (75‐unit single site)	Washington, USA	High unconditional
Buchanan (2006)	Respite care	Provides short‐term shelter along with access to additional services (food, case management and referrals to permanent housing is provided). Conditional upon being capable of living in a drug and alcohol free environment	No intervention	Congregate	Chicago, Illinois, USA. Between October 1, 1998, and December 31, 2000	Moderate conditional
Buchanan (2009)	The Chicago Housing for Health Partnership (CHHP)	Two strands within the intervention, one is respite care and case management the other, for those unable to abstain from alcohol or drugs, is referral to shelter with case management	Unclear	Usual treatment: Referrals to overnight shelters or to interim housing providers. All usual care participants were eligible to receive case management through an existing Ryan White program in the hospital‐affiliated HIV/AIDS clinic	Chicago, Illinois, USA. October 2003–May 2006	High, conditional and unconditional, depending on participant
Cheng (2007)	HUD‐VASH	HUD‐VASH: VA intensive case management were linked to Section 8 housing vouchers, which provide rent subsidies to low‐income individuals with disabilities	Usual treatment: standard VA homeless services, which consisted of short termbroker case management linking users to VA and community services	Not specified	San Francisco, California (N = 107); San Diego, California (N = 91); New Orleans, Louisiana (N = 165); and Cleveland, Ohio (N = 97).Around 1992	Moderate unconditional
Gilmer (2010)	Full‐Service Partnerships (FSP)	The FSP programs implemented in San Diego County provide a combination of subsidized permanent housing and team based services with a focus on rehabilitation and recovery	No treatment	Some scattered, some congregate	San Diego, Caliifornia USA. Between October 2005‐June 2008	High conditional
Goering 2011	Chez Soi—Housing First	The Housing First model used here involves the provision of permanent, private housing units to qualifying individuals, with consumer choice on services and housing location being fundamental	Usual treatment: treatment as usual in each of the current systems of care; does not mean “no care”	Mix of both depending on city and intervention given. Congregate specifically in vancouver	Five Canadian cities of Vancouver, Winnipeg, Toronto, Montreal and Moncton	High unconditional
Goldfinger (1999)	Assigned to group homes, or assigned to independent apartments.	The seven group homes each accommodated between 6 and 10 tenants with shared living, dining, recreational, and kitchen facilities, but separate bedrooms. They provided 24‐h daily coverage, with project staff constantly at hand. All study participants were provided with an intensive case manager. Each participant met with the case manager at least once a week for counselling, hands‐on help with daily activities, and help with access to needed services	High unconditional: participants were given an individual apartment and case manager, all were encouraged,but not required, to participatein community mental healthcentre programs55 scattered housing	63 to congregate housing	Boston, Massachusetts, USA. 18 Months (January 1991 and March 1992)	High unconditional
Gulcur (2003)	Housing First	The experimental Housing First programme offered immediate access to independent housing without requiring psychiatric treatment or sobriety	Continuum of Care: users begin with outreach programmes and drop‐in centres, and then progress through a series of congregate living arrangements with varying levels of on‐site support	Independent housing (scattered)	New York, New York, USA	High unconditional
Howard (2011)	Crisis House or Patient preference of Crisis House	Womens Crisis Housing was available at two London centres where there were also psychiatric wards. The women's crisis houses were located in ordinary residential streets, had a domestic atmosphere and were funded by the UK National Health Service (NHS). Staff were available 24 h per day and were either nurses or healthcare workers with a background in mental health.	Usual Treatment: Usual NHS psychiatric hospital care	Congregate – Crisis houses	London, UK, Around 2007	Moderate conditional
Hwang (2011)	Supportive housing	Tenants had access to a shared kitchen facility, a drop‐in center offering meals and outreach services, as well as a medical and dental clinic providing free services. Individuals accepted into the program received rental subsidies and paid rent‐geared‐to‐income (not exceeding 30% of income). Specifically, tenant support workers assisted residents with mental illness to transition into the housing program.	Usual Treatment, but waitlist (no housing)	Congregate, 84 units in one building	Toronto, Canada. Between 2005 and 2008	High conditional
Kertesz (2007)	ACH Vs NACH Vs Control	All participants were offered behavioral day treatment services and randomly assigned to receive either no program‐provided housing during treatment (no housing), program provided housing contingent upon abstinence (abstinence‐contingent housing), or program‐ provided housing not contingent upon abstinence (nonabstinence‐contingent housing).	Usual outpatient treatment program	Not specified	Birmingham, Alabama, United states	Intervention 1, high conditional; Intervention 2, high unconditional
Larimer (2009)	Housing First	Participants were given a room at an apartment building. No treatment requirements, but on‐site case managers work to engage residents about substance use and life goals. Meals and on‐site health care services are also offered. No behavioural conditions are placed on participants.	Waitlist	Not specified	King county, Washington, United states	High unconditional
Levitt (2013)	Home to stay	The Home to Stay pilot was focused on 3 strategies: moving families out of shelter rapidly using a locally funded, temporary housing subsidy; securing sufficient household income to enable families to pay market rent on expiration of the subsidy; and connecting families to community‐based services that would help them to maintain housing stability after the termination of Home to Stay services.	Usual Treatment, servicestaffing and delivery vary widely across the 150New York City DHS family shelters, but sheltercaseworkers are typically assigned mixed caseloadsof approximately 25 families.	Not specified	New York City, New York, USA. Around 2010–2012	Moderate conditional
Lim (2017)	NYNY IIII	The NYNY III program was for young adults aging out of foster care provides affordable housing and access to various supportive services to help achieve independent lives, including case management, job training, and education support, and provides connections to health services.	Usual Treatment: government‐subsidized housing programs	Not specified	New York City, New York, USA. 2007–2010	High unconditional
Lim (2018)	New York Supportive Housing Program	The program followed the Housing First model with housing placement not being contingent on adhering to treatment or services	No treatment	Not specified	New York City, New York, USA. 2007–2010	High unconditional
Lipton (2000)	Intervention 1: High Intensity Housing Intervention 2: Moderate Intensity Housing Intervention 3: Low Intensity Housing	High‐intensity settings are exclusively dedicated to persons with serious mental illness. It had the highest intensity of housing requirements and services. Residents in moderate intensity settings have their own rooms or studio apartments, and cooking facilities were shared. Tenants at low‐intensity sites hold legally binding leases for individual furnished private rooms or small studio type apartments, with access to either shared or private bathrooms and cooking facilities.	No Intervention	Intervention 1: Congregate Intervention 2: Congregate Intervention 3: Mix of congregate and Scattered	New York City, New York, USA. 1990–1995	Intervention 1, high conditional; Intervention 2, moderate conditional
McHugo (2004)	Integrated housing services program	The integrated housing services approach provided comprehensive mental health services through intensive case management and housing services through dedicated teams that controlled a variety of housing settings	The ACT teams assisted users in finding and affording housing	Mostly congregate housing	Washington, USA	High unconditional
Milby (1996)	Enhanced Care	Some received abstinent contingent work therapy (44.9% of EC subjects) and housing (37.7% of EC subjects). Work therapy, day treatment focused on relapse prevention, social skills training, goal review, weekend planning, community resources for homeless persons.	Usual Treatment: twice weekly group and individual counselling, referral for medical treatment, housing and other agencies. Less frequent aftercare visits.	Not specified	Birmingham, Alabama, United States. Recruited between April 1990‐August 1991, not done beyond this.	High conditional
Milby (2000)	Day treatment +	Day treatment met week days from 07:30‐14:00 h and included lunch and transportation to and from shelters. The following groups were conducted: participant governed morning meeting, process group, AIDS education, relapse prevention training, goal development, goal review, assertiveness training, and many more services.	Usual treatment: once weeklyindividual and group counselling to substance abuseday treatment which included unique interventions forhomelessness in addition to substance abuse.	Group housing: congregate	Birmingham, Alabama, United States	High conditional
Milby (2008)	CM and CM+ (Contingency Management plus behavioral day treatment)	The study compared the abbreviated treatment model (offering contingency‐managed housing, vocational training and work therapy, i.e. CM) to the full treatment model (CM+), which included the same interventions plus extensive behavioral day treatment	Offering contingency‐managed housing, vocational training and work therapy.	Not specified	Birmingham, Alabama, USA. Participants were recruited, randomized, and treated from 2001 to 2004	High conditional
O'Connell (2012)	Housing and Urban Development–Veterans Affairs Supported Housing (HUD‐VASH) Intensive Care Management (ICM)	HUD VASH: intensive case management [ICM] plus rent subsidy vouchers ICM: Intensive case management only	Usual Treatment	Not specified	New Haven, Connecticut, USA. Around 1992–1995	Moderate unconditional
Sadowski (2009)	Housing and Case management (HOUSING FIRST)	Subjects are offered interim housing upon discharge from enrolling hospitalizations, followed by stable housing within 90 days. They have a case manager at each stage (hospital, respite/interim housing, and stable housing)	Usual Treatment: these patients receive usual social services for hospital discharge planning	Mix of scattered and congregate	Chicago, Illinois, USA. Around 2008	High unconditional
Shern (1997)	New York Street Study—specialised housing	The Boston project compared congregate consumer‐run housing with independent living. In New York specialized housing for homeless persons with severe mental illness was the primary housing resource. The San Diego project tested the importance of Section 8 housing certificates in obtaining and maintaining housing.	Usual treatment, usually some sort of case management	Varied. Some congregate. Some scattered	Baltimore, Boston, San Diego, New York City, USA	Moderate conditional
Siegel (2006)	Supported Housing vs community residences	Two types of supported housing. (1) tenants, mostly living alone, reside in studio or one‐bedroom apartments. No preconditions (e.g. sobriety) for housing, with ACT also provided. (2) Sobriety a requirement. Could be asked to leave if they did not maintain good neighbour status—for example, without too many complaints from neighbors. On‐site crisis services are continuously available to tenants in coordination with a New York City psychiatric emergency service	Community Residences: The three agencies that operate thenine community residences provideintensive supportive services in theresidences, which are only for personswith mental illness.	Supported Housing (congregate) vs. community residences, control (scattered)	New York City, USA	Intervention 1, high unconditional; Intervention 2, high conditional
Sosin (1996)	Housing and case management Case management alone	Housing and case management: This is conditional on abstinence and complying with treatment plan. The housing intervention provided the case management model along with supported housing. Brokerage case management without direct provision of services	No Treatment—"The users placed in the control condition were referred by the relevant short‐term program staff to an outpatient or inpatient substance abuse agency, to welfare offices''	Not specified	Chicago, United States. Recruitment around 1991–1992, intervention took place around 1995	Moderate conditional
Srebnik (2013)	Housing First	Intervention is characterized by rapid placement from homelessness directly into permanent housing, supported by assertive on‐site engagement and services but no requirement to participate or to achieve or maintain sobriety	No treatment	Congregate: BAH set aside 20 units at a newly renovated downtown building	King County, the City of Seattle, Washington, USA	High unconditional
Stefancic and Tsemberis (2007)	Pathways (HOUSING FIRST) Consortium (HOUSING FIRST)	Pathways to Housing (HOUSING FIRST) and Consortium (HOUSING FIRST) both provide Housing First services, in the form of independent scatter‐site apartments and ACT. Pathways had a more straightforward HOUSING FIRST approach, whereas Consortium was a newly formed mix of treatment and housing agencies from within the county but with no prior experience operating Housing First	Usual Treatment: usual array of services that included shelter basedprograms and transitional housing	Scatter Site	New York City, USA. 2000–2002	High unconditional