We identified 18 studies that evaluated the effect of high intensity case management on housing stability and/or homelessness (39, 40, 44-46, 48, 50, 52-54, 59, 60, 69-71, 76, 80, 83). High intensity case management included interventions which were described as using either Assertive Community Treatment (ACT; N=12) or intensive case management (ICM; N=6). The included interventions varied in terms of ratio of clients per case manager, frequency of contact, length of treatment and follow-up, location of appointments, degree of service provision versus referral, and team versus individual approach to case management.
The interventions in the majority of the included studies (N=13) are compared to usual services (44-46, 48, 50, 54, 59, 60, 69-71, 80, 83). One study compared the intervention to another type of high intensity case management (76) and two studies compared it to low intensity case
management (53, 69). In two of the included studies, multiple intervention arms or comparison arms were relevant for this category of interventions (39, 40). In one study we have combined two intervention arms that both employed slightly differing versions of assertive community treatment into one intervention group compared to usual services (40). In the other study (39), we combined two comparison arms that both offered usual services to participants into one comparison group compared to the intervention.
Services provided as part of “usual services” varied greatly between and within the studies. We have chosen to include all studies that compared high intensity case management to “usual services” in one comparison. The term “usual services” covers a wide variety of services, but generally refers to the variety of services available to any person meeting the eligibility criteria of the study and not an alternative intervention which participants who are not randomized to the intervention group receive. Usual services in the included studies included drop-in centres, provision of a list of services and information (69), case management style services (59) and
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limited peer coaching (83). Control conditions were too poorly described in most studies to accurately document what participants had access to.
1.A.1. High intensity case management compared to usual services
We identified 18 studies (39, 40, 44-46, 48, 50, 52-54, 59, 60, 69-71, 76, 80, 83) which evaluated the effect of high intensity case management compared to usual services on housing stability and homelessness in the USA (N=15), United Kingdom (N=2) and Denmark (N=1). The included studies were conducted over a long span of time; however, the majority of studies were conducted or began before the end of 2000 (N=12).
Fifteen of the included studies focused on adults with mental illness and/or substance abuse issues (39, 40, 44, 45, 48, 50, 52-54, 59, 60, 69-71, 76). One study focused on disadvantaged youth (46), one study included adults with families (80), and one study targeted recently released criminal offenders (83). While the studies differed slightly in the populations targeted, all of the studies included participants with mental illness and/or substance abuse even when that was not the main identifying characteristic of the target population. Information regarding mental illness and
substance abuse was not reported for the study on disadvantaged youth; however, there was little reason to assume that this group would react differently to the intervention. More importantly, given the outcomes analysed here, housing stability and homelessness, one can assume that this is a universally sought after outcome, and the characteristics of the population might not be
considered to be important. Below is a description of the results.
Primary outcome: Housing stability
Six of the included studies examined housing stability for adults with mental illness and/or substance dependence issues (45, 46, 50, 54, 59, 60, 69).
We carried out a meta-analysis for number of days in stable housing, pooling available data from four included studies (46, 50, 60, 69, 71) to examine the effect of high intensity case management compared to usual services on number of days in stable housing. As evident from the forest plot (Figure 2), the pooled analysis indicates that the high intensity case management leads to an increase in the number of days spent in stable housing compared to usual services (SMD=0.90, 95% CI=0.00 to 1.79). Although considerable heterogeneity is indicated by I2 and Chi2 (I2=98%, chi2=186.17), this is expected due to the complexity of the included interventions, the geographical range of included studies (multiple cities across USA, and Australia) and the wide range of when the interventions were implemented.
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Figure 2: Number of days in stable housing, 12-24 months follow-up, high intensity case management vs usual services
We carried out a meta-analysis to estimate the number of participants in stable housing at 12-18 months after the start of the intervention, pooling available data from two included studies (45, 54). As evident from the forest plot (Figure 3), the pooled analysis indicates that high intensity case management leads to a greater number of individuals living in stable housing compared to usual services (RR=1.26, 95% CI= 1.07 to 1.49). While the heterogeneity was assessed as being high (I2=73%, chi2=3.64), this can be accounted for by differences in when the interventions were implemented (approximately 15 years between publications) and assessed and geographical differences (UK and USA). Together these differences may have implications for political or social contexts which may, in turn, have impacted, for example, the type of usual services being provided.
Figure 3: Number of participants in stable housing, 12-18 months follow-up, high intensity case management vs usual services
It is uncertain whether high intensity case management improves either the length of time
individuals spend in their longest recorded residence, the number of clients who do not move (45), or the number of moves during the last half of a one or two year period (45).
One study reported that there was no difference between the intervention and control groups in the number of moves reported during the previous 12 months as measured at 24 months MD=0.30 (-0.04, 0.64) (46).
Primary outcome: Homelessness
Thirteen of the included studies examined homelessness (39, 44-46, 48, 50, 54, 59, 60, 70, 71, 80, 83). Seven studies reported outcomes related to length of time homeless, either in terms of number of months (44) or number of days (39, 46, 50, 60, 71, 80).
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We carried out a meta-analysis for the number of days spent homeless, pooling available (adjusted) data from six included studies (39, 46, 50, 60, 71, 80). One of the studies adjusted the results for demographic characteristics, specifically ethnicity (60). This study (60) also reported both number of days homeless in shelter and number of days homeless on streets. It was not possible to combine the data from these two outcomes (means and the standard error of the mean (SEM) were
reported, but not the number of participants who reported experiencing these living
arrangements), so we have chosen to include the number of days homeless in shelter in this meta-analysis. The pooled estimate indicates that high intensity case management leads to fewer days spent homeless compared to usual services. Although there is considerable heterogeneity (I2=58%, chi2=11.77), this may be explained by a wide range of geographical settings (USA and Australia), and large differences in when the interventions were implemented and assessed (from 1990s to 2006). Together these differences may have implications for political or social contexts which may, in turn, have impacted, for example, the type of usual services being provided.
Figure 4: Number of days homeless, 12-24 months, high intensity case management vs usual services
In one study (44), high intensity case management seemed to lead to fewer months homeless (mean number of months per 100 months homeless). However, the 95% confidence interval indicates that high intensity case management might make little or no difference the amount of time spent homeless (results as reported in original publication: n=-1.5 [95% CI -4.3 to 1.3], p=0.29).
One study reported that participants in the high intensity case management group reported
spending almost half as many days living on the street than participants in the usual services group (MD=0-14.10 (-15.77, -12.43)) (60)
Three studies reported whether participants experienced homelessness during the study period (44, 48, 83). We conducted a meta-analysis for the number of participants who experienced at least one episode of homelessness within one to two years, pooling data from two studies (48, 83). The third study was not included in the analysis due to incomplete reporting of results (baseline and follow-up percentage of participants was not reported, only the pre-post difference in percentage of participants who experienced homelessness during a two year period was reported along with the difference in difference (44).
The pooled analysis, shown in Figure 5, indicates that high intensity case management may lead to little or no difference in whether individuals experience homelessness during a one to two year
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period compared to usual services. Results, as reported in the original publication, from the third study support this (Bell 2015 (44): OR=0.83, 95% CI=0.60 to 1.17).
Figure 5: Number of participants who experienced at least one episode of homelessness, 12-24 months, high intensity case management vs usual services
Three studies examined the number of participants who reported being homeless at the last follow-up point (12 to 18 months after baseline) (54, 59, 70). We conducted a meta-analysis for the
number of participants who were homeless 12 to 18 months after the beginning of the study, pooling available data from three studies (54, 59, 70). One study reported the percentage of participants per group, but not the total number per group (amount of data on participants varied according to outcome), so we calculated the total number of participants per group using the information provided (70). As evident from the forest plot (Figure 6), the pooled analysis indicates that high intensity case management probably leads to fewer individuals who report being
homeless at the 12 to 18 month follow-up interview compared to usual services (RR=0.59, 95%
CI=0.41 to 0.87).
Figure 6: Number of participants who were homeless at last follow-up point, 18 months, high intensity case management vs usual services
The results and quality assessments for high intensity case management compared to usual services on housing stability and homelessness for adults with mental illness and/or substance abuse problems are summarized in Table 4. The complete GRADE evidence profile is shown in Appendix 8, Table 8.1.1.
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Table 4: Summary of findings table for the effects of high intensity case management compared to usual services (Bell 2012, Bond 199, Cox 1998, Grace 2014, Garety 2006, Killaspy 2006, Nordentoft 2010, Nyamathi 2015, Toro 1997)
Patient or population: adults who are homeless or at-risk of becoming homeless Setting: USA,
Intervention: high intensity 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 high intensity case
management Number of participants homeless at
follow-up
assessed with: self-report follow up: range 12 months to 18 months
Number of participants living in stable community housing at follow-up assessed with: self-report follow up: range 12 months to 18 months
Number of participants who experienced some homelessness assessed with: not reported follow up: 24 months
Number of days homeless assessed with: self-report follow up: range 12 months to 24 months
- SMD 0.27 SD fewer
(0.46 fewer to 0.09 fewer) - 1198
(6 RCTs) ⨁⨁◯◯
LOW 6
Mean number of days in stable housing
assessed with: self-report follow up: range 12 months to 24 months
- SMD 0.09 SD more
(0 to 1.79 more) - 1140
(5 RCTs) ⨁◯◯◯
VERY LOW 1,2
Number of days in longest residence during previous 6 months
assessed with: not reported follow up: 12 months
The mean number of days in longest residence during previous 6 months was 160.9 days
The mean number of days in longest residence during previous 6 months in the intervention group was 16,3 days fewer (CI not reported)
- 58
(1 RCT) ⨁◯◯◯
VERY LOW 10,11
Number of clients who did not move during previous 6 months
assessed with: not reported follow up: 12 months
21 (62%) of HICM participants and 17 (77%) of usual services
participants did not moved during this period (x2(1)=1.47, ns). 58
(1 RCT) ⨁◯◯◯
VERY LOW 10,11
Mean number of moves during previous 6 months
assessed with: not reported follow up: 12 months
Participants in the HICM Group reported M=0.56 moves compared to M=0.29 for the usual services Group (t(53)=-1.39, ns).
58 (1 RCT) ⨁◯◯◯
VERY LOW 10,11
*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; SMD: Standardised mean difference; RR: Risk ratio; MD: Mean difference
1. Risk of performance bias in all studies. Risk of attrition bias in three studies, risk of detection bias in two studies and risk of selection bias in one study.
Inadequate reporting of randomization and/or allocation concealment methods in two studies and blinding of outcome assessors in one study.
2. Considerable heterogeneity (I2=98%, chi2=186.17).
3. Risk of performance bias.
4. Fewer than 300 participants.
5. Risk of performance bias in all studies. Risk of attrition bias in one study.
6. Risk of performance bias in four studies, risk of detection bias in two studies, risk of attrition bias in two studies and other risks of bias in two studies.
Unclear reporting of selection bias in four studies and detection bias in two studies.
7. Two studies includd in the pooled analysis (N=515). One study not included in the analysis, but shows a similar result: Bell 2012 (intervention N=567, control N=563) OR=0.83, 95%CI=0.60, 1.17.
8. Inadequate reporting of randomization, allocation concealment and blinding methods in two studies.
39 The Campbell Collaboration | www.campbellcollaboration.org 9. Total number of events is less than 300.
10. Risk of detection bias and attrition bias. Inadequate reporting of blinding methods for participants and personnel.
11. Fewer than 400 participants.
12. Two studies included in the pooled analysis (Garety 2006 (54), Killaspy 2006). Nordentoft 2010 (N=496) showed that the intervention led to fewer homeless participants at 12 month follow-up than the control group (OR=0.53, 95%CI=0.3, 0.9).
13. Risk of performance bias in four studies, risk of detection bias in two studies, risk of attrition bias in two studies and other risks of bias in two studies.
Unclear reporting of selection bias in four studies and detection bias in two studies.
What does the evidence say?
High intensity case management compared to usual services:
• Probably reduces the number of individuals who are homeless after 12-18 months (moderate certainty evidence).
• May increase the number of the number of people living in stable housing after 12-18 months (low certainty evidence).
• May lead to little or no difference in the number of individuals who experience some homelessness during a two year period (low certainty evidence).
• May reduce the number of days an individual spends homeless (low certainty evidence).
• It is uncertain whether high intensity case management leads to a difference in the number of days an individual spends in stable housing, the number of days an individual spends in their longest residence, and the number of individuals who do or do not move (very low certainty evidence).
1.A.2. High intensity case management compared to low intensity case management
We identified three studies (40, 52, 53) that examined the effects of integrated high intensity case management compared to standard case management (lower intensity) on housing stability and homelessness. The integrated treatment was based on the assertive community treatment model of case management in all three studies. Integrated treatment differs from standard case
management models in that it integrates treatment for substance abuse and mental health issues into one service.
In one study (40), participants were randomized to either assertive community treatment, assertive community treatment with a community worker or brokered case management. The primary authors’ most central hypothesis was that assertive community treatment was better for clients with serious mental health issues than brokered case management. This focus fits with the aim of our review and we therefore attempted to combine results from the two assertive community treatment groups to compare them to the brokered case management group (usual services). For the purpose of this review we are interested only in the assertive community treatment condition and have thus combined the two interventions which employed the assertive community treatment model of case management. In this study the assertive community treatment model was expanded and modified: staff were instructed to visit shelters and were trained in engaging with homeless persons.
In two studies (52, 53), the high intensity case management interventions were based on the assertive community treatment model and were provided by two sites (health centres).
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Primary outcome: Stable housing
Three studies (40, 52, 53) examined the effect of assertive community treatment compared to standard clinical case management on the number of days participants reported living in stable housing. In the first study (40), the total number of participants was not reported, and despite contacting the study authors, the information was not available. We therefore only report the results as they are reported in the study: High intensity case management led to more days spent in stable housing compared to low intensity case management (F=3.54, df=2, 129, p<0.032). The assertive community treatment group reported more days in stable housing than participants in the other two groups: at the 18 month follow-up participants in the assertive community treatment group reported a mean of 23.70 days (SD=11.42) in stable housing during the previous month compared to 18.98 (SD=13.89) for the assertive community treatment with community workers group, and 16.02 days (SD=14.77) for the broker case management group. The authors conclude that “[t]he results provide substantial, although not complete, support for the study' s most central prediction: assertive community treatment is a more effective intervention for people with serious mental illness who are at risk of homelessness than is broker case management” (40), p. 502).
We carried out a meta-analysis for stable housing, pooling available data from two studies (52, 53).
The pooled analysis indicates that high intensity case management may make little or no difference to the amount of time spent in stable housing compared to low intensity case management
(SMD=0.10 [95% CI -0.10 to 0.29], I2=0%) (Figure 7).
Figure 7: Mean number of days spent in stable housing, 36 months (high intensity case management vs low intensity case management)
The results and quality assessments for high intensity case management compared to low intensity case management are summarized in Table 5. The complete GRADE evidence profile is shown in Appendix 8, Table 8.1.2.
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Table 5: Summary of findings table for the effects of high intensity case management vs lowintensity case management (Drake 1998, Essock 2006, Morse 1997)
Patient or population: individuals with mental illness and substance abuse problems Setting: USA
Intervention: high intensity case management Comparison: low intensity case management
Outcomes Anticipated absolute effects* (95% CI) Relative
effect (95% CI)
№ of participants (studies)
Quality of the evidence (GRADE) Risk with low intensity
case management Risk with high intensity case management
Mean number of days spent in stable housing
assessed with: self-report follow up: 36 months
- SMD 0.1 SD higher
(0.1 lower to 0.29 higher)2 - 458 (3 RCTs)3 ⨁⨁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; SMD: Standardised mean difference
1. Risk of detection bias in one study. Inadequate reporting of methods in both studies.
2. The third study that could not be included in the pooled analysis (Morse 1997).The third study reported that HICM led to more days in stable housing (F=3.54, df=2, 129, p<0.032).
3. While only two studies are included in the analysis reported here (total population of 401 participants), the outcome is examined in three studies (total population of 458 participants).
What does the evidence say?
High intensity case management compared with low intensity case management for individuals with mental illness and substance abuse problems:
• May lead to little or no difference in the number of days people spend in stable housing (low certainty evidence).
1.A.3. High intensity case management compared to other intervention (no case management or housing program)
The study (83) that examined the effect of high intensity case management compared to another intervention that did not include case management or housing on housing stability and
homelessness included three trial arms. The first comparison (high intensity case management compared to usual services) is included above. The high intensity case management intervention is described above, and the comparison condition consisted of peer coaching with brief nurse
counselling which was identical to the peer coaching component of the intervention program, but lacked the case management component.
Primary outcome: Homelessness
Results from the included study (83) showed that approximately 10% of intervention group
Results from the included study (83) showed that approximately 10% of intervention group