New research: More evidence that county jail incarceration harms health, raising death rates

The health burdens of jail expansion are heaviest in places that already lock a lot of people up. Those places also would see the largest benefits from decarceration, including fewer deaths each year.

by Jacob Kang-Brown, June 24, 2025

It is tough to get nationally-representative, individual-level data on incarceration’s health impacts. But researchers are increasingly providing evidence that the criminalization of poverty, addiction, and mental health issues has sharp harmful consequences. Jailing in general is associated with higher mortality (death) rates. At the community level, higher levels of jailing causes more communicable and noncommunicable disease, mortality, and harms maternal health. For individual people, jailing has major impacts on mental health and maternal-child health.

A new cohort study by a group of scholars at the U.S. Census Bureau, the Hennepin Healthcare Research Institute, and the medical school at Mount Sinai published in the medical research journal, JAMA Network Open adds to the evidence and has important local policy implications. This study, led by Dr. Utsha Khatri, found that people incarcerated on a given day in 2008 had a 39% higher risk of death compared to similar people who were not incarcerated, and their risk of overdose death was 208% higher. Additionally, the paper suggests that expanding the use or size of local jails is associated with more deaths county-wide. These nationally-representative findings build upon previous research linking incarceration and mortality.

What makes this paper particularly useful for policymakers and advocates is its effort to measure the impacts of both individual experiences of incarceration and county jail incarceration rates. County jail rates measure how much a given county relies on jailing as a response to issues of health and safety.¹ How counties use their jails varies widely across the United States; the jail incarceration rate in Nashville is over five times the rate in Minneapolis, to cite just one example.² This new study drew county-level jail rates from the Vera Institute’s Incarceration Trends Project dataset and leveraged local variation to better understand how jails impact death rates, breaking out overdose deaths for special attention. One caveat worth noting on the individual-level impacts: because millions of people flow through local jails each year, the findings in the study may understate the harms of incarceration.³

Health harms of incarceration affect everyone, making jail expansion versus decarceration a matter of life and death

This study found that people incarcerated on a single day in 2008 had a 39% higher risk of death — and a 208% higher risk of death by overdose — compared to similar people who were not incarcerated. These results are from models that adjust for individual- and county-level factors, and it’s worth noting that having been incarcerated had a much stronger impact on risk of death than other measures linked to death rates like income, education, or indigeneity (that is, whether one identifies as American Indian or Alaska Native). Similarly, the estimated impact of incarceration on overdose mortality was higher than many other individual-level risk factors.

The elevated risk of death from overdose after incarceration is well documented: criminalization of addiction causes a lot of harm. But other research has shown that incarceration is associated with a wide range of health issues, which may help explain the increased risk of death from any cause. People are entering and exiting the toxic prison and jail environment all the time, either upon their arrest and release or as staff clock in and clock out. Other studies have found links between incarceration and health outcomes ranging from:

• All-cause mortality, or general death rates
• Cancer mortality (and stronger effects for liver and lung cancers)
• Chronic lower respiratory disease mortality
• Communicable disease mortality
• COVID-19 outbreaks, cases, and deaths, both inside incarceration facilities and in the community
• Heart disease mortality
• Preterm births
• Substance use disorders mortality
• Suicide

This study by Khatri et al. also found county-level jail incarceration was associated with an increase in deaths generally. The researchers estimate that a local jail incarceration rate 10% higher than the national county average leads to a 0.45% increased risk of death across the board. While this is much smaller than the 39% higher risk for people that were incarcerated, it applies to all people. The authors do the math and it works out to an additional 4.6 people dying for every 100,000 people in the population a year. This relationship is linear: for each 10% increment over the average, a county experiences another 4.6 additional deaths per 100,000 people, so a county with a jail rate 20% higher than average could expect 9.2 additional deaths per 100,000 and so on. Because large increases in jailing are common after new jail construction, and many counties have sustained lower jail rates after COVID-related changes in 2020, it’s worth applying this finding to larger numbers and the associated annual numbers of deaths.

Comparing two suburbs can illuminate the relationship between jail rates and county deaths: Contra Costa County, in the San Francisco Bay Area, reduced its jail population by 25% between 2019 and 2024. In contrast, Baldwin County, Ala. (between Mobile and Pensacola) is opening a new jail this summer that will expand capacity by 50%. The study from Khatri et al. suggests Contra Costa’s 25% jail population reduction (on top of an already relatively low incarceration rate) could translate to an average of 52 fewer county residents dying each year as a result of the harms from the jail. For perspective, Contra Costa averaged 47 homicides a year over the last decade, so this would be a meaningful change. Conversely, if the number of people in the Baldwin County jail increases by 50% to fill up the new facility, this study suggests an additional 57 deaths in the county each year. Given there were only 20 murders in the county in 2023, this would be quite a concerning increase.

For people who live in counties considering steps to reduce criminalization, pretrial detention, and overall jail capacity, this research provides clear evidence of the harms of incarceration. Jail construction is expensive and tends to crowd out public investment in other needs like community-based healthcare. Criminalization of addiction doesn’t address problematic substance use, and better community-based treatment options are needed. Moreover, some studies suggest jail construction leads to even more criminalization rather than deterring crime. Decarceration is one of the best tools to combat early deaths caused by this dynamic between criminalization, incarceration, and austerity — what geographer Ruth Wilson Gilmore terms “organized state abandonment.” By comparing the number of deaths due to the harms of incarceration to the numbers of murders reported, we can get a sense of the scale of this abandonment. Communities across the United States don’t have to tolerate these burdens of incarceration. Instead, as this new paper suggests, working to reduce jailing could help improve community health.