A study led by University of California San Francisco (UCSF) has found that people who are experiencing homelessness have a 16-fold higher rate of sudden death from heart attacks, as well as other causes. The study focused on San Francisco County, which has one of the US’s highest concentrations of homeless people. It found that the rate of sudden cardiac death was seven times higher than the general population.

Some of these deaths may have been prevented with defibrillators and other public policy measures to improve health in this vulnerable population, according to the authors. The paper was published in JAMA Internal Medicine.

“Homeless individuals die young, at a mean age of 50 years,” said corresponding and senior author Zian Tseng, MD, a cardiologist and professor of medicine at UCSF. “Our study sheds light into the contribution of sudden death to the homeless population. We found both cardiac and non-cardiac causes, such as overdoses and unrecognised infections, are much higher among homeless individuals dying suddenly.

“These findings offer several novel insights into the profound impact of homelessness on sudden death and its underlying causes,” Tseng said.

Researchers tracked the autopsies of 868 people in the county who had sudden deaths. Of these, 151 were homeless. They were younger (56 years old compared to 61) and more likely to be male, with a higher prevalence of alcohol and substance use, as well as psychiatric conditions, especially schizophrenia and bipolar disorder.

Researchers found that homeless individuals died most often from non-cardiac causes, while housed individuals died more frequently from arrhythmic causes. Non-cardiac causes, including drug overdoses, gastrointestinal disorders, and infection, were more common in homeless people. Paramedic response times were similar between both population groups.

“While the high rate of substance use in the homeless population has long been recognised, our study demonstrates its association with early, sudden mortality, and its true impact among the homeless,” said first author Leila Haghighat, MD, a cardiology fellow at UCSF.

“By contrast, housed individuals more closely reflected the classic profile of sudden death that modern medical systems aim to resuscitate and prevent,” she said. “Public health interventions such as increasing the availability of automatic external defibrillators and redoubled efforts to treat substance use and targeted immunisation efforts might be helpful to reduce sudden mortality.”