Four new studies examine health, climate, and policy changes facing unhoused populations
Four recent studies by CCPR Faculty Fellow Professor Randall Kuhn and CCPR Affiliate Professor Kathryn Leifheit, examining the impact of the January 2025 fires on people experiencing homelessness, medical concerns facing unsheltered homeless adults, health effects of criminalization among unhoused persons, and factors associated with rising homelessness, have been published and received media coverage.
The “Impact of the January 2025 Los Angeles firestorm on people experiencing homelessness” was published in the April edition of the American Journal of Public Health. In this study, researchers integrated measures of firestorm impact into an ongoing longitudinal survey of people experiencing homelessness. They found that nearly 77% of survey respondents reported life disruption or injury as a result of the firestorm. Unsheltered vehicular respondents and unsheltered public respondents were more likely to report having their lives in danger, being injured, experiencing damage to their living space, damage or loss of belongings, having to evacuate, and difficulty finding shelter compared to sheltered or housed respondents. Moreover, those in evacuation zones more frequently reported evacuation, prolonged smoke exposure, and difficulty finding shelter.
Published in the March edition of Health Affairs Scholar, “What are the true medical concerns facing unsheltered populations?” Professor Kuhn and collaborators estimate behavioral and physical health conditions among unsheltered populations. Leveraging data from a probability-based survey of adults experiencing homelessness, and electronic health records from two field-based medical providers, they find the median prevalence for mental health conditions to be 40%, and 33% for substance use. Post-traumatic stress disorder and major depression were the most common mental health conditions (median 22%). Stimulant use disorder was the most common substance use condition (median 17%). Physical health conditions were more common than both mental health and substance use conditions overall (median 57%).
Another study co-authored by Professor Randall Kuhn, titled “Criminalizing homelessness: Longitudinal associations of police encounters and homeless sweeps with psychosocial health among the unhoused community in Los Angeles,” was recently published in the March edition of Social Science & Medicine. The research utilizes monthly survey data from a prospective cohort of unhoused individuals in Los Angeles County to evaluate how police encounters and homeless sweeps affect both physical and psychosocial well-being over time. The study found that experiencing police encounters and sweeps was associated with poorer self-rated physical health and increased psychological distress within the same month. Additionally, police encounters were linked to same-month increases in feelings of loneliness. The data indicate that these adverse health effects were partially mediated by experiences of displacement. The researchers suggest that enforcement-related displacement likely disrupts individuals’ established physical and social environments, which in turn contributes to negative health outcomes. In addition, greater cumulative exposure to both police encounters and sweeps was consistently associated with poorer overall physical and psychosocial health over time.
Led by Professor Kathryn Leifheit and recently published in JAMA Network Open, “Factors associated with rising homelessness within US States, 2019 to 2014,” sheds light on the macroeconomic and weather forces underpinning changes in homelessness. This longitudinal cohort study measures the association between changing state-level factors and the relative change in the number of people experiencing homelessness. Researchers utilized publicly available datasets spanning the five years to examine state-year average rents, unemployment, pandemic-era housing supports, substance use, immigration, and weather-related property damage. Researchers found that tenant protections and weather changes are salient predictive factors in rising homelessness. Specifically, for each additional 1% of person-time covered by an eviction moratorium was associated with a lower increase in homelessness from 2019 to 2024. In addition, a significant increase was observed for each home-equivalent lost to weather-related events per 10, 000 population. By contrast, average rents, unemployment, emergency rental assistance, and substance use were not associated with year-over-year change in homelessness. Their findings suggest that to attenuate surges in homelessness, policymakers should prioritize actions that prevent evictions and address changing weather.
“Impact of the January 2025 Los Angeles Firestorm on People Experiencing Homelessness”
“What are the true medical concerns facing unsheltered homeless adults?”
“Factors Associated with Rising Homelessness Within the US States, 2019 to 2024”
