That people experiencing homelessness have worse health outcomes than those who are housed is understood. However, the extent of this disparity, especially as it pertains to mortality, has not been examined nationally or with representative data. This paper addresses that gap by providing the first national calculation of mortality for people experiencing homelessness in the United States. In doing so, the authors provide novel insights into the health risks associated with homelessness.

To examine this phenomenon, the authors follow for 12 years 140,000 sheltered or unsheltered homeless people counted in the 2010 Census, by far the largest and closest to representative sample of this population ever analyzed. They compare homeless individuals’ mortality vs. the housed US population overall and for sub-groups defined by age, gender, race, Hispanic ethnicity, disability status, and income (in the latter case, to examine homelessness as a risk factor for mortality that is distinct from poverty in general). The authors further examine mortality differences within the homeless population by type of homelessness, geography, demographic characteristics, income, employment status, and the extent of observed family connections. Their findings include the following:

• Non-elderly people who have experienced homelessness face 3.5 times higher mortality risk than people who are housed, accounting for differences in demographic characteristics and geography. 
• This disparity far exceeds the mortality gap between Black and white housed individuals (1.4), and between poor housed and all housed individuals (2.2).
• Importantly, homelessness is associated with 60 percent greater mortality risk than poverty alone. 
• Homeless individuals’ mortality risk is four times higher in their 30s and 40s. Beginning in their 50s, homeless individuals’ mortality hazard begins to converge with people who are housed, which may reflect both excess mortality of exceptionally vulnerable homeless individuals at younger ages, and shared health vulnerabilities for elderly homeless and housed individuals. 
• Black homeless individuals have about 27 percent lower mortality risk than white homeless individuals, perhaps related to the lower prevalence of substance abuse and behavioral health issues among Black homeless individuals, among other factors. 
• Homeless individuals without formal employment, those with lower incomes, and those without observed family connections are especially vulnerable. 
• Increased mortality risks also hold for sheltered homeless individuals, which illustrates the substantial health risks faced by people experiencing homelessness even when they are not sleeping on the streets.
• Finally, regarding COVID-19: Homeless individuals’ mortality rose by 33 percent during the pandemic. While the proportional rise in mortality risk was similar for people who were housed (29.8 percent) and poor and housed (33.9 percent), the pandemic affected a much larger share of the homeless population because of their substantially elevated baseline mortality risk. 

Bottom line: This work shines a bright light on health issues related to homelessness, which has drawn renewed interest recently in light of the epidemic of deaths from opioids and the impact of COVID-19 on the homeless community. The authors’ findings are broadly summarized in one startling illustration: A 40-year-old homeless person has a mortality risk similar to a housed person who is nearly 60, and a poor housed person who is nearly 50. This fact, among the many others revealed in this work, not only adds to the emerging picture of the persistent hardships and stark health disparities associated with homelessness, but also informs future analysis of safety net and other programs meant to aid the homeless.