Programmatic impact of 5 years of mortality surveillance of New York City homeless populations

Meeting the Health and Social Needs of America's Unhoused and Housing-Unstable Populations: A Position Paper From the American College of Physicians

Access to safe and stable housing has both a direct and indirect effect on health. Experiencing homelessness and housing instability can induce stress and trauma, worsening behavioral health and substance use. The absence of safe and stable living conditions can make it challenging to rest, recuperate, and recover from health ailments and can pose barriers to treatment adherence. Homelessness and housing instability is associated with high rates of numerous diseases and chronic conditions. Its cyclical relationship with other social drivers of health can exacerbate health disparities. As a result, unhoused persons experience unique health challenges and require a health care system and professionals designed to meet their distinct needs. Physicians and other health professionals have a role in educating themselves about the needs of unhoused patients as well as making themselves aware of community and government resources available to these populations. Policymakers must support health professionals in these efforts by supporting the data infrastructure needed to facilitate these referrals to resources, supporting research into best practices for caring for these populations, and investing in community-based organization capacity. Policy action is needed to address the underlying drivers of homelessness, including a dearth of affordable housing, while also addressing the short-term need for safe shelter now. In this position paper, the American College of Physicians (ACP) recognizes the need to address universal access to housing to fulfill one's right to health. ACP offers several recommendations to prevent homelessness and promote the necessary health care and social needs of unhoused populations.

Persistent Disparities: Trends in Rates of Sheltered Homelessness Across Demographic Subgroups in the USA

CONTEXT

Homelessness is a public health crisis affecting millions of Americans every year, with severe consequences for health ranging from infectious diseases to adverse behavioral health outcomes to significantly higher all-cause mortality. A primary constraint of addressing homelessness is a lack of effective and comprehensive data on rates of homelessness and who experiences homelessness. While other types of health services research and policy are based around comprehensive health datasets to successfully evaluate outcomes and link individuals with services and policies, there are few such datasets that report homelessness.

METHODS

Gathering archived data from the US Department of Housing and Urban Development, we created a unique dataset of annual rates of homelessness, nationally, as measured by persons accessing homeless shelter systems, for 11 years (2007-2017, including the Great Recession and prior to the start of the 2020 pandemic). Responding to the need to measure and address racial and ethnic disparities in homelessness, the dataset reports annual rates of homelessness across HUD selected, Census-based racial and ethnic categories.

FINDINGS

Between 2007 and 2017, across all types of sheltered homelessness, whether individual, family, or total, Black, American Indian or Alaska Native, and Native Hawaiian and Pacific Islander individuals and families were far more likely to experience homelessness than non-Hispanic White individuals and families. Particularly concerning about the rates of homelessness among these populations is the persistent and increasing nature of these disparities across the entire study period.

CONCLUSIONS

While homelessness is a public health problem, the hazard of experiencing homelessness is not uniformly distributed across different populations. Because homelessness is such a strong social determinant of health and risk factor across multiple health domains, it deserves the same careful annual tracking and evaluation by public health stakeholders as other areas of health and health care.

Does Housing Status Matter in Emergency Medical Services Administration of Naloxone? A Prehospital Cross-sectional Study

Introduction: Persons experiencing homelessness (PEH) use emergency medical services (EMS) at disproportionately high rates relative to housed individuals due to several factors including disparate access to healthcare. Limited access to care is compounded by higher rates of substance use in PEH. Despite growing attention to the opioid epidemic and housing crisis, differences in EMS naloxone administration by housing status has not been systematically examined. Our objective in this study was to describe EMS administration of naloxone by housing status in the City of Los Angeles. Methods: This was a 12-month retrospective, cross-sectional analysis of electronic patient care reports (ePCRs) for all 9-1-1 EMS incidents attended by the Los Angeles Fire Department (LAFD), the sole EMS provider agency for the City of Los Angeles during the study period, January-December 2018. During this time, the City had a population of 3,949,776 with an estimated 31,825 (0.8%) PEH. We included in the study individuals to whom LAFD personnel had administered naloxone. Housing status is a mandatory field on ePCRs. The primary study outcome was the incidence of EMS naloxone administration by housing status. We used descriptive statistics and logistic regression models to examine patterns by key covariates. Results: There were 345,190 EMS incidents during the study period. Naloxone was administered during 2,428 incidents. Of those incidents 608 (25%) involved PEH, and 1,820 (75%) involved housed individuals. Naloxone administration occurred at a rate of 19 per 1,000 PEH, roughly 44 times the rate of housed individuals. A logistic regression model showed that PEH remained 2.38 times more likely to receive naloxone than their housed counterparts, after adjusting for gender, age, and respiratory depression (odds ratio 2.38, 95% confidence interval 2.15-2.64). The most common provider impressions recorded by the EMS responders who administered naloxone were the same for both groups: overdose; altered level of consciousness; and cardiac arrest. Persons experiencing homelessness who received naloxone were more likely to be male (82% vs 67%) and younger (41.4 vs 46.2 years) than housed individuals. Conclusion: In the City of Los Angeles, PEH are more likely to receive EMS-administered naloxone than their housed peers even after adjusting for other factors. Future research is needed to understand outcomes and improve care pathways for patients confronting homelessness and opioid use.

Housing Status as a Predictor for Outpatient Care Following an Emergency or Urgent Care Encounter with a Behavioral Health Diagnosis: A Multivariable Analysis

Individuals without stable housing experience high rates of mental illness and seek behavioral health care in emergency care settings. Little is known about the effect of homelessness on outpatient follow-up after utilizing emergency or urgent care for behavioral health care. Patient encounters with behavioral health diagnoses among 7 emergency department (ED) or urgent care (UC) locations over 4 years were used to determine the correlation between housing status and outpatient follow-up within 90 days. Of 1,160,386 visits by 269,615 unique patients, 55,738 (23%) encounters included a behavioral health diagnosis. Patients with stable housing were twice as likely to follow up with a primary care provider (PCP) and with an outpatient behavioral health provider than patients without housing (aOR 2.60; aOR 2.00, p < 0.0001). Homelessness is associated with difficulty in accessing follow-up behavioral health care. UCs and EDs may use specific interventions to improve outpatient follow-up.

Invasive Pneumococcal Disease Clusters Disproportionally Impact Persons Experiencing Homelessness, Injecting Drug Users, and the Western United States

BACKGROUND

Invasive pneumococcal disease (IPD) isolates forming genomic clusters can reflect rapid disease transmission between vulnerable individuals.

METHODS

We performed whole genome sequencing of 2820 IPD isolates recovered during 2019 through Centers for Disease Control and Prevention's Active Bacterial Core surveillance to provide strain information (serotypes, resistance, genotypes), and 2778 of these genomes were analyzed to detect highly related genomic clusters.

RESULTS

Isolates from persons experiencing homelessness (PEH) were more often within genomic clusters than those from persons not experiencing homelessness (PNEH) (105/198 [53.0%] vs 592/2551 [23.2%]; P < .001). The 4 western sites accounted for 33.4% (929/2778) of isolates subjected to cluster analysis yet accounted for 48.7% (343/705) of clustering isolates (P < .001) and 75.8% (150/198) of isolates recovered from PEH (P < .001). Serotypes most frequent among PEH were (in rank order) 12F, 4, 3, 9N, 8, 20, and 22F, all of which were among the 10 serotypes exhibiting the highest proportions of clustering isolates among all cases. These serotypes accounted for 44.9% (1265/2820) of all IPD cases and are included within available vaccines.

CONCLUSIONS

We identified serotype-specific and geographic differences in IPD transmission. We show the vulnerability of PEH within different regions to rapidly spreading IPD transmission networks representing several pneumococcal serotypes included in available vaccines.

The Determinants of Length of Homeless Shelter Stays: Evidence-Based Regression Analyses

Objective: To identify determinants that contribute to the length of homeless shelter stay. Methods: We utilized a unique dataset from the Homeless Management Information Systems from Boston, Massachusetts, United States, which contains 44,197 shelter stays for 17,070 adults between Jan. 2014 and May 2018. Results: Our statistical analyses and regression model analyses show that factors that contribute to the length of a homeless shelter stay include being female, senior, disability, being Hispanic, or being Asian or Black African. A significant fraction of homeless shelter stays (76%) are experienced by individuals with at least one of three disabilities: physical disability, mental health issues, or substance use disorder. Recidivism also contributes to longer homeless shelter stays. Conclusion: The results suggest possible program and policy implications. Several factors that contribute to longer homeless shelter stay, such as gender, age, disability, race, and ethnicity, may have funding implications. Age may point to the need for early interventions. Disability is developmental and may benefit from treatment and intervention. Finally, we find that length of stay and recidivism are not independent, and may form a vicious cycle that requires additional investigation.

Invasive Pneumococcal Strain Distributions and Isolate Clusters Associated With Persons Experiencing Homelessness During 2018

BACKGROUND

We aimed to characterize invasive pneumococcal disease (IPD) isolates collected from multistate surveillance in the United States during 2018 and examine within-serotype propensities of isolates to form related clusters.

METHODS

We predicted strain features using whole genome sequencing obtained from 2885 IPD isolates obtained through the Center for Disease Control and Prevention's Active Bacterial Core surveillance (ABCs), which has a surveillance population of approximately 34.5 million individuals distributed among 10 states. Phylogenetic analysis was provided for serotypes accounting for ≥27 isolates.

RESULTS

Thirteen-valent pneumococcal conjugate vaccine (PCV13) serotypes together with 6C accounted for 23 of 105 (21.9%) of isolates from children aged <5 years and 820 of 2780 (29.5%) isolates from those aged ≥5 years. The most common serotypes from adult IPD isolates were serotypes 3 (413/2780 [14.9%]), 22F (291/2780 [10.5%]), and 9N (191/2780 [6.9%]). Among child IPD isolates, serotypes 15BC (18/105 [17.1%]), 3 (11/105 [10.5%]), and 33F (10/105 [9.5%]) were most common. Serotypes 4, 12F, 20, and 7F had the highest proportions of isolates that formed related clusters together with the highest proportions of isolates from persons experiencing homelessness (PEH). Among 84 isolates from long-term care facilities, 2 instances of highly related isolate pairs from co-residents were identified.

CONCLUSIONS

Non-PCV13 serotypes accounted for >70% of IPD in ABCs; however, PCV13 serotype 3 is the most common IPD serotype overall. Serotypes most common among PEH were more often associated with temporally related clusters identified both among PEH and among persons not reportedly experiencing homelessness.

Homelessness and Veteran Status in Relation to Nonfatal and Fatal Opioid Overdose in Massachusetts

BACKGROUND

Compared with non-Veterans, Veterans are at higher risk of experiencing homelessness, which is associated with opioid overdose.

OBJECTIVE

To understand how homelessness and Veteran status are related to risks of nonfatal and fatal opioid overdose in Massachusetts.

DESIGN

A cross-sectional study.

PARTICIPANTS

All residents aged 18 years and older during 2011-2015 in the Massachusetts Department of Public Health's Data Warehouse (Veterans: n=144,263; non-Veterans: n=6,112,340). A total of 40,036 individuals had a record of homelessness, including 1307 Veterans and 38,729 non-Veterans.

MAIN MEASURES

The main independent variables were homelessness and Veteran status. Outcomes included nonfatal and fatal opioid overdose.

RESULTS

A higher proportion of Veterans with a record of homelessness were older than 45 years (77% vs. 48%), male (80% vs. 62%), or receiving high-dose opioid therapy (23% vs. 15%) compared with non-Veterans. The rates of nonfatal and fatal opioid overdose in Massachusetts were 85 and 16 per 100,000 residents, respectively. Among individuals with a record of homelessness, these rates increased 31-fold to 2609 and 19-fold to 300 per 100,000 residents. Homelessness and Veteran status were independently associated with higher odds of nonfatal and fatal opioid overdose. There was a significant interaction between homelessness and Veteran status in their effects on risk of fatal overdose.

CONCLUSIONS

Both homelessness and Veteran status were associated with a higher risk of fatal opioid overdoses. An understanding of health care utilization patterns can help identify treatment access points to improve patient safety among vulnerable individuals both in the Veteran population and among those experiencing homelessness.

Upsurge of Conjugate Vaccine Serotype 4 Invasive Pneumococcal Disease Clusters Among Adults Experiencing Homelessness in California, Colorado, and New Mexico

After 7-valent pneumococcal conjugate vaccine introduction in the United States in 2000, invasive pneumococcal disease (IPD) due to serotype 4 greatly decreased in children and adults. Starting in 2013, serotype 4 IPD incidence increased among adults within 3 of 10 Active Bacterial Core surveillance sites. Of 325 serotype 4 cases among adults in 2010-2018, 36% were persons experiencing homelessness (PEH); incidence of serotype 4 IPD among PEH was 100-300 times higher than in the general population within these 3 areas. Genome sequencing for isolates recovered 2015-2018 (n = 246), revealed that increases in serotype 4 IPD were driven by lineages ST10172, ST244, and ST695. Within each lineage, clusters of near-identical isolates indicated close temporal relatedness. Increases in serotype 4 IPD were limited to Colorado, California, and New Mexico, with highest increases among PEH, who were at increased risk for exposure to and infections caused by these strains.

Drug overdose mortality among residents of single room occupancy buildings in San Francisco, California, 2010-2017

BACKGROUND

Single room occupancy (SRO) buildings, also known as residential hotels, are a form of affordable housing common to cities in North America, and residents of these buildings face elevated rates of substance use, physical and mental multimorbidity, and mortality. Identifying distinct populations at greater risk of overdose death is crucial to the planning of interventions aiming to reduce drug-related mortality, yet no studies have assessed the population burden of overdose mortality among SRO residents. The present study quantifies and characterizes drug overdose mortality among residents of SRO buildings in a large U.S. city.

METHODS

We used mortality records and a database of SRO buildings to calculate rate ratios comparing overdose mortality due to opioids, cocaine, and methamphetamine among SRO residents and non-SRO residents in San Francisco, CA 2010-2017 and assessed bivariate differences in decedent and death location characteristics between SRO resident and other overdose decedents.

RESULTS

There were 1,551 overdose deaths during the study period, with an overall rate of 21.3 per 100,000 residents (95%CI = 20.2-22.6). The rate among SRO residents (278.7, 95%CI = 252.9-306.5) was 19.3 (95%CI = 17.1-21.7) times that of non-SRO residents (21.3, 95%CI = 20.2-22.6). An additional 79 (5%) deaths among non-residents occurred in SRO buildings, and 86% of SRO resident decedents died at home compared to 64% of non-SRO residents (p < 0.05).

CONCLUSIONS

Overdose mortality was substantially higher among SRO residents, who were also more likely to die from overdose at home, which highlights the need for resources and targeted interventions directed towards residents of SRO buildings.

Recommendations of the Advisory Committee on Immunization Practices for Use of Hepatitis A Vaccine for Persons Experiencing Homelessness

Hepatitis A (HepA) vaccination is recommended routinely for children at age 12-23 months, for persons who are at increased risk for hepatitis A virus (HAV) infection, and for any person wishing to obtain immunity. Persons at increased risk for HAV infection include international travelers to areas with high or intermediate hepatitis A endemicity, men who have sex with men, users of injection and noninjection drugs, persons with chronic liver disease, person with clotting factor disorders, persons who work with HAV-infected primates or with HAV in a research laboratory setting, and persons who anticipate close contact with an international adoptee from a country of high or interme-diate endemicity (1-3). Persons experiencing homelessness are also at higher risk for HAV infection and severe infection-associated outcomes. On October 24, 2018, the Advisory Committee on Immunization Practices (ACIP)* recommended that all persons aged 1 year and older experiencing homelessness be routinely immunized against HAV. The ACIP Hepatitis Vaccines Work Group conducted a systematic review of the evidence for administering vaccine to persons experiencing homelessness, which included a set of criteria assessing the benefits and adverse events associated with vaccination. HepA vaccines are highly immunogenic, and >95% of immunocompetent adults develop protective antibody within 4 weeks of receipt of 1 dose of the vaccine (1). HAV infections are acquired primarily by the fecal-oral route by either person-to-person transmission or via ingestion of contaminated food or water. Among persons experiencing homelessness, effective implementation of alternative strategies to prevent exposure to HAV, such as strict hand hygiene, is difficult because of living conditions among persons in this population. Integrating routine HepA vaccination into health care services for persons experiencing homelessness can reduce the size of the at-risk population over time and thereby reduce the risk for large-scale outbreaks.

Burden and Risk Factors for Cold-Related Illness and Death in New York City

Exposure to cold weather can cause cold-related illness and death, which are preventable. To understand the current burden, risk factors, and circumstances of exposure for illness and death directly attributed to cold, we examined hospital discharge, death certificate, and medical examiner data during the cold season from 2005 to 2014 in New York City (NYC), the largest city in the United States. On average each year, there were 180 treat-and-release emergency department visits (average annual rate of 21.6 per million) and 240 hospital admissions (29.6 per million) for cold-related illness, and 15 cold-related deaths (1.8 per million). Seventy-five percent of decedents were exposed outdoors. About half of those exposed outdoors were homeless or suspected to be homeless. Of the 25% of decedents exposed indoors, none had home heat and nearly all were living in single-family or row homes. The majority of deaths and illnesses occurred outside of periods of extreme cold. Unsheltered homeless individuals, people who use substances and become incapacitated outdoors, and older adults with medical and psychiatric conditions without home heat are most at risk. This information can inform public health prevention strategies and interventions.

Mortality among the homeless: Causes and meteorological relationships

Background

The homeless constitute a subpopulation particularly exposed to atmospheric conditions, which, in the temperate climate zone, can result in both cold and heat stress leading to the increased mortality hazard. Environmental conditions have become a significant independent risk factor for mortality from specific causes, including circulatory or respiratory diseases. It is known that this group is particularly prone to some addictions, has a shorter life span, its members often die of different causes than those of the general population and may be especially vulnerable to the influence of weather conditions.

Materials and methods

The retrospective analysis is based on data concerning 615 homeless people, out of which 176 died in the analyzed period (2010–2016). Data for the study was collected in the city of Olsztyn, located in north-east Poland, temperate climatic zone of transitional type. To characterize weather conditions, meteorological data including daily minimum and maximum temperatures and the Universal Thermal Climate Index (UTCI) were used.

Results

The average life span of a homeless person was shorter by about 17.5 years than that recorded for the general population. The average age at death of a homeless male was 56.27 years old (SD 10.38), and 52.00 years old (SD 9.85) of a homeless female. The most frequent causes of death were circulatory system diseases (33.80%). A large number of deaths were attributable to smoking (47.18%), whereas a small number was caused by infectious diseases, while a relatively large proportion of deaths were due to tuberculosis (2.15%). Most deaths occurred in the conditions of cold stress (of different intensity). Deaths caused by hypothermia were thirteen-fold more frequently recorded among the homeless than for the general population. A relative risk of death for a homeless person even in moderate cold stress conditions is higher (RR = 1.84) than in thermoneutral conditions.

Conclusions

Our results indicate excessive mortality among the homeless as well as the weak and rather typical influence of atmospheric conditions on mortality rates in this subpopulation, except for a greater risk of cold related deaths than in the general population. UTCI may serve as a useful tool to predict death risk in this group of people.

Public Health and Vulnerable Populations: Morbidity and Mortality Among People Ever Incarcerated in New York City Jails, 2001 to 2005

The health of people ever incarcerated in New York City (NYC) jails during 2001 to 2005 was characterized by matching jail, shelter, mortality, sexually transmitted infection, HIV, and tuberculosis (TB) data from the NYC Departments of Health and Mental Hygiene, Correction, and Homeless Services. Compared with nonincarcerated people and those living in the lowest income NYC neighborhoods, those ever incarcerated had higher HIV prevalence and HIV case rates. Ever-incarcerated females also had higher rates of gonorrhea and syphilis than nonincarcerated females. Ever-incarcerated people who used the single adult homeless shelter system had higher HIV, gonorrhea, and TB case rates and all-cause mortality rates than ever-incarcerated people without shelter use, when adjusting for other variables. People ever incarcerated in NYC jails are at risk for conditions of public health importance. Sex-specific jail- and community-based interventions are needed.

Differences in Health and Social Support between Homeless Men and Women Entering Permanent Supportive Housing

BACKGROUND

Permanent supportive housing (PSH) is the leading intervention to end chronic homelessness. Little is known, however, about gender differences, including potential disparities in physical and mental health and social support, that might inform services available through PSH.

METHODS

This study included 421 homeless adults, at least 39 years old, English- or Spanish-speaking, who were moving into PSH through 26 different agencies in the Los Angeles area.

RESULTS

Compared with men entering PSH, homeless women (28% of the sample) were younger (p < .01), less likely to have achieved at least a high school education (p < .05), and had lower incomes (p < .01). Women had more chronic physical health conditions (p < .01), were more likely to have any chronic mental health condition (odds ratio, 2.5; p < .01), and had more chronic mental health conditions than men (p < .01). Women had more relatives in their social networks (Coefficient, 0.79, p < .01) and more relatives who provided support (coefficient, 0.38; p < .05), but also more relatives with whom they had conflict (coefficient, 0.19; p < .01). Additionally, women were less likely to have caseworkers (coefficient, -0.59; p < .001) or physical and mental health care providers in their networks (coefficient, -0.23 [p < .01]; coefficient, -0.37 [p < .001], respectively). However, after correcting for multiple testing, three outcomes lost significance: number of chronic physical health conditions, number of relatives who provided any support, and number of relatives with whom there was conflict.

CONCLUSIONS

There is evidence of gender differences in mental health and social support among homeless adults moving into PSH. PSH cannot be a one-size-fits-all approach. Supportive services within housing should be tailored based on gender and other individual needs.

Characteristics of Homeless Adults Who Died of Drug Overdose: A Retrospective Record Review

Drug overdose is a major cause of death among homeless people, but little is known about the characteristics of homeless overdose decedents. We conducted a retrospective record review of 219 adult patients of Boston Health Care for the Homeless Program (BHCHP) who died of drug overdose in 2003-2008. We assessed the substances implicated in overdose and the health and service use characteristics of decedents prior to death. Eighty-one percent of overdose deaths involved opioids and 40% involved multiple drugs. Problem substance use (85%), psychiatric illness (61%), and chronic pain (45%) were common, and 32% had documentation of all three. Half were well-connected to BHCHP, and 35% had a clinic visit within 90 days of death. The complex health histories and frequent health care contacts of homeless drug overdose decedents suggest that clinical facilities may be an important frontline venue for overdose education, naloxone distribution, and integrated substance use treatment programming.

Examining mortality among formerly homeless adults enrolled in Housing First: An observational study

Background

Adults who experience prolonged homelessness have mortality rates 3 to 4 times that of the general population. Housing First (HF) is an evidence-based practice that effectively ends chronic homelessness, yet there has been virtually no research on premature mortality among HF enrollees. In the United States, this gap in the literature exists despite research that has suggested chronically homeless adults constitute an aging cohort, with nearly half aged 50 years old or older.

Methods

This observational study examined mortality among formerly homeless adults in an HF program. We examined death rates and causes of death among HF participants and assessed the timing and predictors of death among HF participants following entry into housing. We also compared mortality rates between HF participants and (a) members of the general population and (b) individuals experiencing homelessness. We supplemented these analyses with a comparison of the causes of death and characteristics of decedents in the HF program with a sample of adults identified as homeless in the same city at the time of death through a formal review process.

Results

The majority of decedents in both groups were between the ages of 45 and 64 at their time of death; the average age at death for HF participants was 57, compared to 53 for individuals in the homeless sample. Among those in the HF group, 72 % died from natural causes, compared to 49 % from the homeless group. This included 21 % of HF participants and 7 % from the homeless group who died from cancer. Among homeless adults, 40 % died from an accident, which was significantly more than the 14 % of HF participants who died from an accident. HIV or other infectious diseases contributed to 13 % of homeless deaths compared to only 2 % of HF participants. Hypothermia contributed to 6 % of homeless deaths, which was not a cause of death for HF participants.

Conclusions

Results suggest HF participants face excess mortality in comparison to members of the general population and that mortality rates among HF participants are higher than among those reported among members of the general homeless population in prior studies. However, findings also suggest that causes of death may differ between HF participants and their homeless counterparts. Specifically, chronic diseases appear to be more prominent causes of death among HF participants, indicating the potential need for integrating medical support and end-of-life care in HF.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2552-1) contains supplementary material, which is available to authorized users.

Estimating the number of homeless deaths in France, 2008-2010

Background

The homeless population of France has increased by 50% over the last 10 years. Studies have shown that homelessness is associated with a high risk of premature death. The aim of this study was to estimate the number of homeless deaths in France between 2008 and 2010, using a reproducible method.

Methods

We used the capture-recapture method to estimate the number of homeless deaths in France using two independent sources. An associative register of homeless deaths was matched with the national exhaustive database of the medical causes of death, using several matching approaches based on various combinations of the following variables: gender, age, place of death, date of death.

Results

The estimated number of homeless deaths between 2008 and 2010 was 6730 (95% CI: [4381–9079]), a number greatly underestimated by the two sources considered separately (less than 20%).

Conclusions

In the absence of a register of the homeless deaths, the capture-recapture method provides an order of magnitude for evaluation of the resources that may be allocated by policy makers to manage the issue. Based on common and routinely produced databases, this estimate may therefore be used to monitor the mortality of the homeless population. Further studies about homeless mortality, particularly on the lead causes of deaths, are needed to manage this issue and to implement strategy to decrease the number of homeless deaths.