Comparative Effectiveness of Single-Site and Scattered-Site Permanent Supportive Housing on Patient-Centered and COVID-19-Related Outcomes for People Experiencing Homelessness, California, 2021-2023 (ICPSR 39155)
Version Date: Aug 28, 2025 View help for published
Principal Investigator(s): View help for Principal Investigator(s)
Benjamin Henwood, University of Southern California;
Lillian Gelberg, University of California-Los Angeles
https://doi.org/10.3886/ICPSR39155.v1
Version V1
Summary View help for Summary
People experiencing homelessness (PEH) were among the most likely to contract the novel coronavirus disease 2019 (COVID-19). Many PEH utilized high-density public places to satisfy their basic needs (e.g., soup kitchens for sustenance, public libraries for restrooms). This made it difficult for them to limit close contact with others and put them at increased risk of contracting and transmitting COVID-19. Furthermore, it was difficult to follow recommended protective measures--such as handwashing and social distancing--when living in shelters or on the streets.
PEH were at higher risk of COVID-19 related hospitalization and death than the rest of the population. The poor living conditions of PEH accelerated aging, leading them to experience geriatric conditions and medical complications more typical of individuals 10-20 years older. They were also at increased risk of cardiovascular and respiratory disease, HIV/AIDS, and diabetes, all conditions that increase vulnerability to serious COVID-19-related complications and death. These risks were compounded by the fact that PEH also faced significant barriers to accessing quality health care. In the absence of protective action, it was estimated that more than 21,000 PEH would require hospitalization due to COVID-19, more than 7,000 would require critical care, and nearly 3,500 would die.
Consequently, the COVID-19 pandemic made housing and health care for PEH one of the top priorities for the U.S. health care and public health systems. State and local governments across the country used federal relief funds to allocate private hotel rooms as protective shelter for vulnerable PEH. In Los Angeles County (LAC), which contains the largest unsheltered homeless population in the nation, 2,400 PEH were placed in hotels. COVID-19 response plans included accommodating up to 15,000 PEH in hotels who would then be moved to permanent housing in 90 days. This rapid push into housing amid a pandemic necessitated a delicate balance between social distancing and maintaining patients' basic needs, continuity of existing care, and personal and social well-being.
Permanent supportive housing (PSH)--programs that provide immediate access to independent living situations coupled with support services--is the most effective approach for serving PEH. Numerous studies have demonstrated PSH's effectiveness in improving housing retention, quality of life, and HIV outcomes. Though evidence concerning its impact on other health outcomes, health behaviors, and health care utilization is limited, the National Academies of Sciences, Engineering, and Medicine has nonetheless recognized PSH as extremely beneficial for PEH's health. COVID-19 was what this organization termed a "housing-sensitive condition"--one whose transmissibility, course, and medical management are particularly influenced by homelessness. Consequently, the National Alliance to End Homelessness recommended the use of PSH as part of its framework to address COVID-19 and homelessness.
However, significant questions remain about what types of PSH programs can best address COVID-19-related risk and promote patient-centered outcomes at a time of social and community disruption. There are two distinct approaches to implementing PSH: place-based (PB) PSH, or single-site housing placement in a congregate residence with on-site services, and scattered-site (SS) PSH, which uses apartments rented from a private landlord to house clients while providing mobile case management services. The strengths and weaknesses of these two approaches remain largely unknown but may have direct implications for adherence to COVID-19 prevention protocols and other health-related outcomes.
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Access to these data is restricted. Users interested in obtaining these data must complete a Restricted Data Use Agreement, specify the reasons for the request, and obtain IRB approval or notice of exemption for their research.
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Data Collection Notes View help for Data Collection Notes
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Qualitative data (interviews) were collected by the researchers for this study, but they are not currently available and it's not known when or if they will be available.
Study Purpose View help for Study Purpose
The purpose of this study was to understand the comparative effectiveness of Place-Based - Permanent Supportive Housing (PB-PSH) and Scattered-Site - Permanent Supportive Housing (SS-PSH) on patient-centered quality of life, health care utilization, and health behaviors that would reduce COVID-19 risk by following a diverse sample of People Experiencing Homelessness (PEH) who were assigned to either PB-PSH or SS-PSH for 6 months. A secondary objective was to identify barriers and facilitators that may have affected PSH implementation during the pandemic and its aftermath. This was achieved via qualitative interviews with a purposive subsample of PEH and focus groups conducted with housing service providers.
The specific aims of the study included to:
1. Test the comparative effectiveness of PB-PSH and SS-PSH on COVID-19-related health behaviors (COVID-19-related personal health practices including social distancing, testing, and vaccine uptake) for PEH over time;
2. Test the comparative effectiveness of PB-PSH and SS-PSH on patient-centered quality of life (i.e., general life satisfaction; physical, mental, social, and environmental health) for PEH overtime;
3. Test the comparative effectiveness of PB-PSH and SS-PSH on health care utilization, health behaviors, and unmet need for care for physical health, mental health, substance use disorders for PEH overtime;
4. Contextualize quantitative findings from Aims 1-3 through a longitudinal qualitative inquiry with participants from PB-PSH and SS-PSH that were purposively sampled using maximum variation sampling based on demographic and health characteristics; and
5. Understand service providers', policy makers', and other stakeholders' perspectives on challenges of implementing PSH and sustaining COVID-19-related prevention practices and continuity of care in PSH.
Study Design View help for Study Design
This study utilized a mixed-methods comparative prospective longitudinal study design to examine the comparative effectiveness of Place-based - Permanent Supportive Housing (PB-PSH) and Scattered-Site - Permanent Supportive Housing (SS-PSH) in promoting COVID-19 protective behaviors among people experiencing homelessness. Recruitment for this study was extended from 6 months to 18 months and began in January 2021 and ended in July 2022.
A significant surge in COVID-19 infections in Los Angeles County (LAC) during this time precluded in-person enrollment and, instead, recruitment depended on housing case managers already interacting with People Experiencing Homelessness (PEH) as part of the housing placement process who informed anyone approved for PSH (or Rapid Rehousing with support services) about the study. PEH were eligible if they: a) were 18 years or older; b) had been approved for PSH; c) could be interviewed in English or Spanish; and d) were willing and able to provide informed consent. Enrollment included PEH in LAC who had either moved into housing within the preceding two weeks or were expected to move into housing within 30 days. Case managers across 26 different housing agencies assisted interested and eligible PEH in setting up a meeting with study staff via phone or zoom to complete the enrollment process. This included obtaining informed consent using electronic signature.
After enrolling in the study, participants were provided smartphones with unlimited talk, text, and data plans that were used to send links via text message to a web-based survey. Participants first completed a 20-minute, self-administered baseline survey to capture basic information on demographic characteristics and their housing and health histories. To help reduce the burden involved in completing a lengthy questionnaire at the time of enrollment, a follow-up survey link was sent approximately one day later to collect additional baseline outcome measures and then monthly thereafter for 6 months. Baseline and follow-up surveys were collected between February 2021 and June 2023.
Participants who did not respond to monthly surveys sent via text message or who requested additional support were able to complete the survey via phone interview, with answers entered by study staff. To reduce respondent fatigue and relieve trauma, the survey employed a trauma-informed design including plain language, readable font size, and extensive buffering language to prepare respondents for difficult questions. All survey items also included a "Prefer not to answer" option, which was deemed critical to reducing respondent burden. Participants received a $15.00 electronic gift card incentive for a completed baseline survey and for each completed monthly survey thereafter. Study protocols were approved by the University of Southern California Institutional Review Board.
Sample View help for Sample
Convenience sample of people experiencing homelessness in Los Angeles County who had either moved into permanent supportive housing unit within the preceding two weeks or were expected to move into housing within 30 days. Case managers across 26 different housing agencies assisted interested and eligible PEH in setting up a meeting with study staff via phone or zoom to complete the enrollment process.
Time Method View help for Time Method
Universe View help for Universe
People experiencing homelessness who moved into a permanent supportive housing unit in Los Angeles County, California between the years 2021 to 2023.
Unit(s) of Observation View help for Unit(s) of Observation
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Description of Variables View help for Description of Variables
This study contains two datasets. Dataset #1 contains 529 variables. Dataset #2 is the exact same file but with the addition of 181 constructed / computed variables added by the P.I. The data files contained questions about the educational status, employment, monthly income, health insurance status, drug use, political affiliation, the total time the participants have experienced homelessness in their life time, and their experience with COVID-19 among others.
The datasets also included additional demographic variables such as: gender identity, sexual orientation, race, age, and gender among others.
Presence of Common Scales View help for Presence of Common Scales
The following scales (or select items from the scales) were used in collection of data for this study:
Original Release Date View help for Original Release Date
2025-08-28
Version History View help for Version History
2025-08-28 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:
- Checked for undocumented or out-of-range codes.
Notes
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One or more files in this data collection have special restrictions. Restricted data files are not available for direct download from the website; click on the Restricted Data button to learn more.