Federal law defines people experiencing homelessness as those who lack a fixed, regular, and adequate nighttime residence designed for sleeping. This includes individuals and families facing the imminent loss of their housing with no subsequent housing identified and victims of domestic violence or sexual assault who are living in a dangerous or life-threatening situation.¹ Chronic homelessness is defined as continuous homelessness for at least one year or at least four episodes of homelessness in the previous three years.²

Demographics

Measuring the prevalence of homelessness and the demographic characteristics of the homeless population is difficult because they are ever changing. Most surveys rely on personal reports and may have a limited reach. Table 1 reviews approximate demographics of the homeless population.^1–4 Table 2 lists risk factors for becoming homeless and for increased morbidity and mortality in the homeless population.^5–7

The increased risk of homelessness for those experiencing extreme poverty is exacerbated by a lack of affordable housing. On average, low-income American households use at least one-half of their income for housing, further limiting their resources and putting them at risk of homelessness. The supply of low-cost housing has continued to decline since 1980.⁸ In 2017, the hourly wage needed to afford the average two-bedroom rental home in the United States was nearly $14 higher than the federal minimum hourly wage of $7.25.⁸ Black and Hispanic communities are disproportionately affected by the scarcity of low-income housing because of the persisting effects of systemic housing discrimination.⁸

Screening for Homelessness

Housing instability is often grouped with other adverse social conditions associated with poor health, such as food insecurity and social isolation. These are collectively referred to as social risk factors.⁹ Social risk factors are associated with increased mortality, disease rates, and use of medical resources, and multiple risk factors often affect one individual or family.¹⁰

Screening for social risk factors in primary care is ideally paired with mechanisms for referral to social services or, at a minimum, incorporated into a care plan.^11–13 Although multiple screening tools are available, outcomes data on their use are limited.^14,15 Research on the use of screening tools for housing instability in the general population is also limited.¹⁶

In 2012, the Veterans Health Administration integrated a two-question screening tool for housing instability into electronic health records^17,18:

1. In the past two months, have you been living in stable housing that you own, rent, or stay in as part of a household? (Negative response indicates homelessness.)

2. Are you worried or concerned that in the next two months you may not have stable housing that you own, rent, or stay in as part of a household? (Positive response indicates risk of homelessness.)

This screening, which is completed at all outpatient appointments, has resulted in earlier identification of homelessness and increased referrals for services.¹⁷ Once identified, people experiencing homelessness should be screened for risk factors that may increase their morbidity and mortality risk, including female sex, having been homeless for more than five years, history of adverse childhood events, history of substance use, low education level, and prior incarceration or military service.^8,19

The Initial Clinic Visit

During the initial clinic visit with a person experiencing homelessness, physicians should dedicate time to identifying the patient’s main priorities. These patients may have multiple health conditions, likely with competing nonmedical priorities.^6,20 Physicians and people experiencing homelessness tend to have different perceptions of the barriers to optimal disease management.²¹ Identifying these discrepancies can help build trust and establish shared priorities, a process that is crucial to the success of the visit and follow-up plans.³