A small number of homeless people keep the ER busy, according to UCSF researchers

By Maureen McInaney

Efforts to reduce Emergency Department (ED) use among the homeless should focus on the needs of the small percentage that seek care repeatedly, according to a new study by UCSF researchers.

Though other population-based studies of the homeless have shown high rates of ED use, this study is among the first to look at repeat utilization among individuals, according to lead investigator, Margot Kushel, MD, UCSF assistant professor of medicine at San Francisco General Hospital Medical Center (SFGHMC).

The study appears in the May 2 issue of the American Journal of Public Health.

The researchers determined that 40 percent of homeless people in San Francisco had one or more emergency department visits in the prior year (three times the national norm).  However, 7.9 percent of these patients, the high users, accounted for 54.5 percent of the visits. Frequent users of the ED (defined as those with four or more visits in the previous year) were more likely to have substance abuse and mental health problems than overall ED users and represent an extreme example of the complications of homelessness, according to the researchers.

Kushel also noted that respondents who were marginally housed, spending all of their nights in single room occupancy hotels and no nights on the street, were significantly less likely to use the ED or to be high users. “This suggests that addressing the housing issue may lead to decreased ED use, particularly among frequent users,” she said. “The effects of lack of housing—including exposure to violence, difficulty managing chronic medical conditions and planning for health care—may increase ED use.”

Researchers sampled 2,578 English-speaking homeless and marginally housed adults in San Francisco. At the time of the survey, it was estimated that there were about 5,000 literally homeless persons living on the street or in homeless shelters in San Francisco and between 6,000 and 8,000 people staying in low-rent hotels. High users of the ED tended to be younger, female, homeless versus marginally housed, and Medicaid or Medicare insured (as opposed to uninsured). In addition to mental illness and substance abuse, other factors associated with high ED use included: poorer health status and involvement in crime (either perpetrator or victim).

Additional researchers, all affiliated with San Francisco General Hospital Medical Center (SFGHMC), include: Sharon Perry, PhD, statistician in the department of epidemiology and biostatistics; David Bangsberg, MD, PhD, UCSF assistant professor of medicine and director of the Epidemiology and Prevention Interventions Center (EPI-Center); Richard Clark, MPH, project director in the department of epidemiology and biostatistics; and Andrew Moss, PhD, UCSF professor in the department of epidemiology and biostatistics.
Kushel’s work was supported, in part, by a faculty development grant (for general internal medicine) from the Department of Health and Human Services. Bangberg’s work was supported, in part, by the Doris Duke Charitable Foundation.