The effectiveness of substance use interventions for homeless and vulnerably housed persons: A systematic review of systematic reviews on supervised consumption facilities, managed alcohol programs, and pharmacological agents for opioid use disorder

PLoS One. 2020 Jan 16;15(1):e0227298. doi: 10.1371/journal.pone.0227298. eCollection 2020.


Background: Substance use is disproportionately high among people who are homeless or vulnerably housed. We performed a systematic overview of reviews examining the effects of selected harm reduction and pharmacological interventions on the health and social well-being of people who use substances, with a focus on homeless populations.

Methods and findings: We searched MEDLINE, EMBASE, PsycINFO, Joanna Briggs Institute EBP, Cochrane Database of Systematic Reviews and DARE for systematic reviews from inception to August 2019. We conducted a grey literature search and hand searched reference lists. We selected reviews that synthesized evidence on supervised consumption facilities, managed alcohol programs and pharmacological interventions for opioid use disorders. We abstracted data specific to homeless or vulnerably housed populations. We assessed certainty of the evidence using the GRADE approach. Our search identified 483 citations and 30 systematic reviews met all inclusion criteria, capturing the results from 442 primary studies. This included three reviews on supervised consumption facilities, 24 on pharmacological interventions, and three on managed alcohol programs. Supervised consumption facilities decreased lethal overdoses and other high risk behaviours without any significant harm, and improved access to care. Pharmaceutical interventions reduced mortality, morbidity, and substance use, but the impact on retention in treatment, mental illness and access to care was variable. Managed alcohol programs reduced or stabilized alcohol consumption. Few studies on managed alcohol programs reported deaths.

Conclusions: Substance use is a common chronic condition impacting homeless populations. Supervised consumption facilities reduce overdose and improve access to care, while pharmacological interventions may play a role in reducing harms and addressing other morbidity. High quality evidence on managed alcohol programs is limited.

Publication types

  • Research Support, Non-U.S. Gov't
  • Systematic Review

MeSH terms

  • Alcohol-Related Disorders / epidemiology
  • Alcohol-Related Disorders / rehabilitation*
  • Drug Overdose / epidemiology
  • Drug Overdose / prevention & control*
  • Harm Reduction
  • Health Services Accessibility / organization & administration
  • Health Services Accessibility / statistics & numerical data
  • Housing / organization & administration
  • Housing / statistics & numerical data
  • Humans
  • Ill-Housed Persons / psychology
  • Ill-Housed Persons / statistics & numerical data*
  • Narcotic Antagonists / therapeutic use
  • Observational Studies as Topic
  • Opiate Substitution Treatment / methods
  • Opiate Substitution Treatment / statistics & numerical data
  • Opioid-Related Disorders / epidemiology
  • Opioid-Related Disorders / rehabilitation*
  • Prevalence
  • Program Evaluation
  • Systematic Reviews as Topic
  • Treatment Outcome
  • Vulnerable Populations / psychology
  • Vulnerable Populations / statistics & numerical data*


  • Narcotic Antagonists

Grants and funding

This systematic review was funded by Inner City Health Associates, Toronto, Canada. The funders of the study had no role in the study design, data collection, data analysis, data interpretation, or the writing of the report. The corresponding author had full access to all of the data in the study and had final responsibility for the decision to submit for publication.