Description of the included studies
We found six studies with eight comparisons on the effects of abstinence-contingent housing programs (26, 58, 66-68, 75). All of the included studies were conducted in the USA. The data for the included studies were collected between 1991 and 2004. Within the category of abstinence-contingent housing programs, we identified three subcategories (see Table 11).
Table 11: Overview of abstinence-contingent housing programs comparisons
Intervention Comparison
2.A. Abstinence-contingent housing programs with case management
2.A.1. Usual services 2.A.2. Case management 2.B. Abstinence-contingent housing
programs with day treatment 2.B.1. Usual services 2.B.2. Day treatment
2.B.3. Non-abstinence-contingent housing programs with day treatment
2.B.4. Abstinence-contingent housing programs with community reinforcement approach
The above interventions are compared to usual services, or other interventions. That is, abstinence-contingent housing is compared to another active intervention. Table 12 presents an overview of the populations, interventions, comparisons and outcomes in the six included studies. In some studies the duration of the intervention is reported and differs from the longest follow-up point. In these instances we have reported both the duration of the intervention and the longest follow-up point.
Table 12: Description of studies that evaluated effects of abstinence-contingent housing Study (ref);
country Population
(N, eligibility) Intervention, Duration, FU (FU) in mos (mos), N
Comparison, N Primary outcome
Kertesz 2007 housing with day treatment
Duration: 6 mos FU: 12 mos N=63
Day treatment only N=66
Non-abstinence-contingent housing with day treatment N=66
Proportion of participants in stable housing >45 of previous 60 days
Milby 1996 (67),
USA N=176 homeless,
substance dependence
Abstinence-contingent housing, vocational training and work therapy with day treatment
Duration: 24 weeks FU: 12 mos N=69
Usual services
N=62 Mean number of
days housed in previous 60 days
51 The Campbell Collaboration | www.campbellcollaboration.org training and work therapy with day treatment
Duration: 24 weeks N=72
Day treatment only
N=69 Mean number of
days housed in previous 60 days
Milby 2010 (68), training and work therapy with community reinfocement approach Duration: 24 weeks FU: 18 mos N=103
Abstinence-contingent housing, vocational training and work therapy
N=103
Proportion of participants housed more than 40 of previous 60 days
Smith 1998 (75),
USA N=106 homeless with
alcohol dependence Abstinence-contingent housing with community reinforcement approach Duration: varied, minimum 3 weeks FU: 12 mos N=64
Abstinence-contingent housing with day treatment housing with case management
Duration: average 6 mos FU: 12 mos
Number of days housed of previous 60 days
Description of the intervention
All of the interventions in the included studies had some component of abstinence-contingent housing. Abstinence-contingent housing in the included studies consisted of program-provided housing for a set period of time (6-8 months) with or without some rent contributed by the participants after the initial phase. Conditionality of tenancy for the participants consisted of a contract agreeing to abstinence and then regular urine testing to screen for substance use. Housing for participants was not segregated (segregated housing is separated from the general public and only for individuals receiving social assistance).
Category 2A: Abstinence-contingent housing with case management
We found one study (26) with two comparisons that examined the effect of abstinence-contingent housing with case management in the USA. Participants were recruited from 1991 to 1992 and randomized to one of three groups: abstinence-contingent housing with the progressive
independence model of case management (ACH+CM), the progressive independence model of case management only (CM), or usual services (US).
The abstinence-contingent housing component consisted of supported housing in low-income apartment blocks where tenancy was contingent upon following program rules (26). The case management component in this study was described as a “progressive independence model” with a
52 The Campbell Collaboration | www.campbellcollaboration.org
focus on providing immediate tangible resources while supporting further treatment for substance abuse and other relevant problems. Case management was also contingent on following a contract which participants signed before the start of the intervention.
Participants in the case management condition received an average of three months care, while participants in the housing with case management condition received an average of six months of care.
Abstinence-contingent housing with case management was compared to usual services (26) and case management only (26). Usual services consisted of aftercare services such as referrals to outpatient or inpatient substance abuse agencies or welfare offices.
2.A.1. Abstinence-contingent housing with case management compared to usual services
One study (26) examined the effect of abstinence-contingent housing with case management compared to usual services.
Primary outcome: Housing stability
Results from the included study (26) show that participants in the intervention group reported more days in housing than participants in the control group at the 12 month follow-up interview (MD=6.4, 95% CI= 6.18 to 6.62). The results for abstinence-contingent housing with case
management compared to usual services only are presented in Table 12. The results are controlled for length of time from baseline to the second follow-up interview, which varied due to difficulties arranging meetings with participants and the number of days in the relevant period spent in a controlled environment (e.g. prison or hospital) since they are not truly homeless or housed during this time. Other control variables such as characteristics which were found to vary across the treatment conditions are also controlled for (being recruited from a particular short-term program, reported perception of health problems at baseline, access to an automobile, having ever been married, having foster care experience as a child or having lived with one’s mother continuously until 18). Not enough information was provided to present the results in a forest plot.
The results and quality assessments for abstinence-contingent housing with case management compared to usual services are summarized in Table 13. The complete GRADE evidence profile is shown in Appendix 8, Table 8.2.1.
53 The Campbell Collaboration | www.campbellcollaboration.org
Table 13: Summary of findings table for the effects of abstinence-contingent housing with case management vs usual services (Sosin 1995)
Patient or population: adults who are homeless or at-risk of homelessness with substance abuse problems Setting: USA
Intervention: abstinence-contingent housing with case management Comparison: usual services
Outcomes Anticipated absolute effects* (95% CI) Relative
effect (95% CI)
№ of participants (studies)
Quality of the evidence (GRADE) Risk with Usual
services Risk with abstinence-contingent housing with case management Housing stability
assessed with: Not reported follow up: 12 months
The mean housing
stability was 0 days The mean housing stability in the intervention group was 6.4 days more (6.18 more to 6.62 more)
- 323
(1 RCT) ⨁◯◯◯
VERY LOW 1,2
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; MD: Mean difference
1. Risk of selection bias and attrition bias. Inadequate reporting of blinding of participants, personnel and outcome assessors.
2. Fewer than 400 participants.
What does the evidence say?
It is uncertain whether abstinence-contingent housing with case management compared to usual services leads to a difference in number of days spent in in stable housing (very low certainty evidence).
2.A.2. Abstinence-contingent housing with case management compared to case management
One study (26) compared abstinence-contingent housing with case management to case management only.
Primary outcome: Housing
Results from this study (26) show that participants in the intervention group (N=108) reported a mean increase of 25.6 days housed of the previous 60 days from baseline to 12 months compared to a mean increase of 21.2 days for the comparison group (N=70). Not enough information was
reported to determine if there is a difference between groups, or to present the results in a forest plot.
The results and quality assessments for abstinence-contingent housing with case management compared to case management only is summarized in Table 14. The complete evidence profile is presented in Appendix 8, Table 8.2.2.
54 The Campbell Collaboration | www.campbellcollaboration.org
Table 14: Summary of findings table for the effects of abstinence-contingent housing with case management services vs case management (Sosin 1995)
Patient or population: adults who are homeless or at-risk of homelessness with substance abuse problems Setting: USA
Intervention: abstinence-contingent housing with case management Comparison: case management
Outcomes Anticipated absolute effects* (95% CI) Relative
effect (95% CI)
№ of participants (studies)
Quality of the evidence (GRADE) Risk with case
management Risk with abstinence-contingent housing with case management Change in number of days
housed from baseline to follow-up assessed with: Self-report follow up: 12 months
The mean change in number of days housed from baseline to follow-up was 21.2 days
The mean change in number of days housed from baseline to follow-up in the intervention group was 4.4 days more (CI not reported)
- 178
(1 RCT) ⨁◯◯◯
VERY LOW 1,2
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; MD: Mean difference
1. Risk of selection bias and attrition bias. Inadequate reporting of blinding of participants, personnel and outcome assessors.
2. Fewer than 400 participants.
What does the evidence say?
It is uncertain whether abstinence-contingent housing with day treatment compared to case management only leads to a difference in the number of days spent in stable housing (very low certainty evidence).
Category 2B: Abstinence-contingent housing with day treatment
Three studies evaluated the effect of abstinence-contingent housing with day treatment in USA (58, 66, 67).
The abstinence-contingent housing with day treatment intervention consisted of two general components: housing programs in which tenancy is conditional upon maintained sobriety and/or treatment, and day treatment (58, 66, 67).
In one study with two comparisons (58), participants were required to pay to remain in housing (but were not removed if unable to pay). The housing component in this study was only part of treatment and available for a maximum of six months. No information was available regarding segregation of the housing or whether it was individual or group housing.
In the second study (67), participants’ tenancy in program management housing was contingent on abstinence. No information was provided in this study regarding rent payment, or the form of housing provided.
In the third study (66), participants were moved into rent free and furnished housing provided by the program after achieving abstinence. Participants in this study received segregated group or individual housing. After phase I half of the clients remained in this housing arrangement, and half moved to program-managed individual houses.
55 The Campbell Collaboration | www.campbellcollaboration.org
In these three included studies (58, 66, 67), participants in the intervention group received day treatment in the first phase of a two phase intervention. The second phase of the intervention included abstinence-contingent work therapy with minimum wage which could be used towards rent payments. Some participants also received aftercare (58) (66). Formal treatment ended after six months (58, 67, 68).
Participants in the comparison groups received usual services (67), day treatment only (58, 66), or non-abstinence-contingent housing with day treatment (58).
2.B.1. Abstinence-contingent housing with day treatment compared to usual services
One study compared abstinence-contingent housing with day treatment to usual services (67).
Primary outcome: Homelessness
Results from the included study (67) showed that participants in the intervention group reported a mean of 52 fewer days homeless in the previous 60 days at 12 month follow-up than in the previous 60 days at baseline. There was no change in number of days homeless for the control group.
The results and quality assessments for abstinence-contingent housing with day treatment compared to usual services is summarized in Table 15. A complete GRADE evidence profile is shown in Appendix 8, Table 8.2.3.
Table 15: Summary of findings table for the effects of abstinence-contingent housing with day treatment vs usual services (Milby 1996)
Patient or population: homeless adults with substance abuse problems Setting: USA
Intervention: abstinence-contingent housing with day treatment Comparison: usual services
Outcomes Impact № of participants
(studies) Quality of the evidence (GRADE) Change in number of days homeless in past 60 days
from baseline to 12 months assessed with: Personal History Form follow up: 12 months
The mean change in number of days homeless in past 60 days from baseline to 12 months was 0 for the control group. The intervention group had a mean change of 52 fewer days homeless from baseline to 12 months, p=0.026.
131 (1 RCT) ⨁⨁◯◯
LOW 1,2
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval
1. Risk of performance bias and attrition bias.
2. Less than 400 participants.
What does the evidence say?
Abstinence-contingent housing with day treatment compared to usual services may lead to fewer days spent homeless (low certainty evidence).
56 The Campbell Collaboration | www.campbellcollaboration.org
2.B.2. Abstinence-contingent housing with day treatment compared to day treatment
Two studies (58, 66) examined the effect of abstinence-contingent housing with day treatment compared to day treatment.
Participants in the comparison groups received day treatment only which was similar to the day treatment offered to the intervention group for months 1-2 and 3-6 (58, 66). These participants were not offered housing.
Primary outcomes: Housing stability and homelessness
Two studies examined the effect of abstinence-contingent housing with day treatment compared to day treatment only on the number of days participants reported being housed during a period of time. In one study (66), participants in both groups reported a greater number days housed of the previous 60 days at 12 months compared to baseline; however, participants in the intervention group showed a greater increase than participants in the control group (MD=18.7 (SE=3.9) compared to MD=16.2 (SE=3.5)) (MD=2.50 [95% CI 1.28 to 3.72]). In the other study (58), participants in the intervention group reported a greater increase in number of days housed from baseline to 12 months (M=17.7 (SD=33.8)) than participants in the control group (M=9.5
(SD=31.0)) (MD=8.20 [95% CI 5.74 to 10.66]).1
When the results were pooled using SMD, I2=86%. Since this heterogeneity could not be explained, we chose not to pool the results (Figure 8).
Figure 8: Days in stable housing, 12 months, abstinence-contingent housing with day treatment vs day treatment only
The results and quality assessments for abstinence-contingent housing with day treatment
compared to day treatment only is summarized in Table 16. The complete GRADE evidence profile is shown in Appendix 8, Table 8.2.4.
1 Kertesz 2007 58. Kertesz SG, Mullins AN, Schumacher JE, Wallace D, Kirk K, Milby JB. Long-term housing and work outcomes among treated cocaine-dependent homeless persons. Journal of Behavioral Health Services & Research.
2007;34(1):17-33. reported standardized deviations, so the review authors converted this number to standard errors since this is a more correct statistic for the data. The data included in this analysis was not available from the publication, but was sent by the study authors to the review team upon request.
57 The Campbell Collaboration | www.campbellcollaboration.org
Table 16: Summary of findings table of the effects of abstinence-contingent housing with day treatment vs day treatment (Kertesz 2007; Milby 1996)
Patient or population: homeless adults with substance abuse problems Setting: USA
Intervention: abstinence-contingent housing with day treatment Comparison: day treatment
Outcomes Anticipated absolute effects* (95% CI) Relative
effect (95% CI)
№ of participants (studies)
Quality of the evidence (GRADE) Risk with day treatment Risk with
abstinence-contingent housing with day treatment
Changes in mean days housed in past 60 days between baseline and 12 months - self-report
assessed with: Retrospective Interview for Housing, Employment, and Treatment History
follow up: 12 months
The mean changes in mean days housed in past 60 days between baseline and 12 months - self-report was 16.2 days
The mean changes in mean days housed in past 60 days between baseline and 12 months - self-report in the intervention group was 5.25 days more (0.34 fewer to 10.83 more)
- 214
(2 RCTs)
⨁◯◯◯
VERY LOW 1,2
Changes in mean days employed in past 60 days between baseline and 12 months
assessed with: Retrospective Interview for Housing, Employment, and Treatment History - self report follow up: 12 months
The mean changes in mean days employed in past 60 days between baseline and 12 months was 0 days
The mean changes in mean days employed in past 60 days between baseline and 12 months in the intervention group was 1.62 days more (0.99 fewer to 4.22 more)
- 214
(2 RCTs) ⨁◯◯◯
VERY LOW 1,2
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; MD: Mean difference
1. Risk of performance bias and attrition bias. Inadequate reporting of allocation concealment in both studies.
2. Less than 400 participants.
What does the evidence say?
It is uncertain whether abstinence-contingent housing with day treatment compared to day treatment only leads to a difference in number of days spent in stable housing or employed (very low certainty evidence).
2.B.3. Abstinence-contingent housing with day treatment compared to non-abstinence-contingent housing with day treatment
One study examined the effects of abstinence-contingent housing with day treatment compared to non-abstinence contingent housing with day treatment (58). The comparison group consisted of an equivalent intervention as the abstinence-contingent housing group; however, continued tenancy was not dependent on sobriety (i.e. the results of the urine tests). Both groups received the day treatment component.
Primary outcome: Housing stability
Results from this study (58) showed that participants in the intervention group reported a greater increase in the number of days in stable housing in the 60 days prior to follow-up between baseline and follow-up (12 months) (MD=17.7 (SD=33.8)) than participants in the control group (MD=14.2 (SD=31.7)).
The results and quality assessments for abstinence-contingent housing day treatment compared to non-abstinence-contingent housing with day treatment for housing stability and homelessness are summarized in Table 17. A complete GRADE evidence profile is shown in Appendix 8, Table 8.2.5.
58 The Campbell Collaboration | www.campbellcollaboration.org
Table 17: Summary of findings table for the effects of abstinence-contingent housing with day treatment vs non-abstinence-contingent housing with day treatment (Kertesz 2007)
Patient or population: homeless adults with substance abuse Setting: USA
Intervention: abstinence-contingent housing with day treatment Comparison: non-abstinence contingent housing with day treatment
Outcomes Anticipated absolute effects* (95% CI) Relative
effect (95% CI)
№ of participants (studies)
Quality of the evidence (GRADE) Risk with non-abstinence
contingent housing with day treatment
Risk with abstinence-contingent housing with day treatment
Days housed - self report Change in mean days housed in past 60 days between baseline and 12 months
assessed with: Retrospective Interview for Housing, Employment, and Treatment History
follow up: 12 months
The mean days housed - self report Change in mean days housed in past 60 days between baseline and 12 months was 0 days
The mean days housed - self report Change in mean days housed in past 60 days between baseline and 12 months in the intervention group was 3.5 days more (1.22 more to 5.78 more)
- 82
(1 RCT) ⨁◯◯◯
VERY LOW 1,2
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; MD: Mean difference
1. Risk of performance bias and attrition bias. Inadequate reporting of allocation concealment.
2. Less than 400 participants.
What does the evidence say?
It is uncertain whether abstinence-contingent housing with day treatment compared to non-abstinence-contingent housing with day treatment leads to a difference in number of days spent in stable housing (very low certainty evidence).
2.B.4. Abstinence-contingent housing with day treatment compared to abstinence-contingent housing with community reinforcement approach
We found two studies that examined the effect of abstinence-contingent housing with day treatment compared to abstinence-contingent housing with community reinforcement approach (68, 75) in the USA.
Participants in one study (68) were provided with a furnished and rent free apartment and vocational training which was contingent on continued sobriety during phase I (weeks 2-8). In Phase II (weeks 3-24) participants were required to pay a small amount of rent (not specified) from program provided stipends. Participants who maintained abstinence were moved to a transitional housing program. In Phase III (week 25-end) continued tenancy in abstinence-contingent program housing was only available when space was available at a modest rent.
In the other study (75), participants were housed in grant-supported housing for a maximum of three months contingent on sobriety. However, participants who had secured a job and saved a
In the other study (75), participants were housed in grant-supported housing for a maximum of three months contingent on sobriety. However, participants who had secured a job and saved a