Research by a UCLA-led team has determined that the number of COVID-19 cases and the number of deaths from the disease both increased dramatically after states lifted eviction moratoriums that had been in place to protect people who were struggling to make rent payments during the pandemic.

The study found that the number of COVID-19 cases doubled and the number of deaths attributable to the disease increased fivefold, in the four-month period after eviction moratoriums expired.

Those figures suggest that during the summer of 2020, there were 433,700 more COVID-19 cases and 10,700 more deaths in the U.S. than there would have been had moratoriums continued. (In all, there were 6.3 million cases of COVID-19 in the U.S. by September 2020, and some 193,000 people died of the disease by that time, according to the U.S. Centers for Disease Control and Prevention.)

Evictions may have accelerated COVID-19 transmission by decreasing individuals’ ability to socially distance,” said Frederick Zimmerman, a professor of health policy and management at the UCLA Fielding School of Public Health and a senior author of the study.

The researchers analyzed data from Washington, D.C., and the 43 states that implemented eviction moratoriums — 27 of which expired before September, and 17 of which extended at least until September. Seven states never implemented an eviction moratorium. The analysis compared the states that allowed their moratoriums to expire to the states that kept them in place; the researchers also accounted for the effects of other public health measures, including COVID-19 testing, school closures, mask mandates and stay-at-home requirements.

The study is published in the American Journal of Epidemiology. The research team also comprised physicians, public health researchers and eviction law specialists from Boston University, Johns Hopkins University, UC San Francisco and Wake Forest University.

Kathryn Leifheit, a postdoctoral scholar at the Fielding School and lead author of the study, said previous research suggested that evictions can lead people to move into crowded housing or homeless shelters.

“Each of those outcomes connotes an increased risk of exposure to COVID-19,” Leifheit said. “And an increased risk of eviction may also have forced people to engage in work that exposed them to COVID-19 transmission.”

The authors acknowledge several limitations of their analysis. Data were not available for the authors to measure the actual numbers of evictions in states whose moratoriums expired. They also could not account for local eviction protections that may have remained in place even after statewide moratoriums expired.

The research was initially published in a preprint form in November. That work was cited in an order (PDF) issued by Dr. Rochelle Walensky, director of the U.S. Centers for Disease Control and Prevention, which extended the federal eviction moratorium to July 31, 2021.

“Specifically, the authors compared the COVID-19 incidence and mortality rates in states that lifted their moratoria with the rates in states that maintained their moratoria,” the order states. “In these models, the authors accounted for time-varying indicators of each state’s test count as well as major public health interventions including lifting stay-at-home orders, school closures, and mask mandates.”

The research was funded in part by the Agency for Healthcare Research and Quality, part of the Department of Health and Human Services; the Robert Wood Johnson Foundation’s Evidence for Action program; and the National Center for Advancing Translational Sciences of the National Institutes of Health, through a Boston University Clinical and Translational Science Institute grant.