The median age of the homeless in San Francisco increased 9 years over the 14-year period 1990–2003. In the most recent sample, one third were aged 50 or older. This aging rate far exceeds that in the general population, and is consistent with trends from 5 North American cities6,13–17
Aging trends among the homeless in 6 North American cities
The aging trend suggests that the homeless population is primarily a static cohort. Homelessness itself became more chronic over time. If people become newly homeless and exit homelessness at a steady rate, we would expect the median duration homeless to remain constant. Instead, our trend data are consistent with a cohort effect beginning in the 1980s that may have been caused by an increase in population size, increasing drug use, and a lack of government response to such changes (D. Culhane, personal communication). Under the cohort model of homelessness, a one-time increase in supportive housing stock may have an important impact on homelessness.
There are several potential sources of bias in our study. Cross-sectional samples drawn at homeless service providers over-sample the chronically homeless and those using services.18
In addition, it is unknown whether the sample was biased by refusals to participate, by limiting the sample to the literally homeless rather than including the near homeless, or by relying on self-reported data. These factors may affect the median age in our sample, but are unlikely to induce a spurious age trend.
The aging we observed may reflect provider changes or shifts in service utilization. However, the trend was robust: increases in age were also seen among users of shelters, meal programs, and SRO hotels not included in the main analysis. Moreover, similar findings have been noted in other cities. It is also possible that fewer newly homeless people were using the agencies we sampled. Homeless youth and homeless families, for example, do not use the same services as the chronically homeless.19
However, samples from a shelter and a meal program that cater to families and young people also showed increasing age. Another possibility is that increasing imprisonment driven by mandatory drug sentencing20
may have progressively removed young persons from the population. However, there is evidence from the largest meal program21
and street and shelter counts22
that the homeless population size may have been actually increasing over the study period. Early in the study period, there were decreases in the number of SRO units due to gentrification and fires, and supportive housing units began opening late in the study period. Supportive housing gives preference to older homeless persons; therefore, these changes may have masked a greater aging trend.
While substance use and mental health remain major medical issues for the homeless, the aging trends we observed suggest that chronic health conditions will take on increasing prominence for homeless health services as the population ages. A recent study reported that 85% of homeless persons over age 50 reported at least 1 chronic medical condition.23
Homeless health care providers will increasingly need to grapple with how to manage their complex chronic conditions. New programs that integrate health care with more stable housing, such as supportive housing, may be important steps for avoiding end-stage disease and institutionalization in older homeless persons with complex medical regimens needing frequent office visits.