COVID-19 Incidence and Mortality in Federal and State Prisons Compared With the US Population, April 5, 2020, to April 3, 2021

Early in the COVID-19 pandemic, case and death rates in US prisons substantially exceeded national rates.¹ Prison systems subsequently reported adopting several policies to contain COVID-19 spread, including limiting social interactions, distributing personal protective equipment, and expediting prisoner releases,^2,3 although failures of infection prevention and control have been documented.^2,4 We examined COVID-19 cases and deaths among US federal and state prisoners during the first 52 weeks of the pandemic and compared these rates with the overall US population, updating a previously published report analyzing COVID-19 incidence and mortality in prisons through June 6, 2020.¹

Counts of COVID-19 cases and deaths among prisoners in all 50 state prison systems and the Federal Bureau of Prisons were collected by the UCLA Law COVID Behind Bars Data Project for 52 weeks from April 5, 2020, to April 3, 2021. Counts were extracted from departments of corrections websites and, as needed, supplemented with data collected by the Marshall Project and the Associated Press.⁵ To calculate rates of COVID-19 in prisons, we used total jurisdictional prison population data reported by the Vera Institute³ for January 1, 2020, July 1, 2020, December 30, 2020, and March 31, 2021. We estimated weekly prison populations by linearly interpolating between the observed dates. For comparison, we also calculated US population COVID-19 rates using cases and deaths reported by the Centers for Disease Control and Prevention,⁶ allowing for a 2-month reporting delay. US population data were taken from the US Census Bureau’s American Community Survey 2019.

We calculated both weekly and cumulative rates of incidence and standardized mortality for the prison population and US population. Weekly prison rates were calculated using the jurisdictional incarcerated population for the corresponding week, while cumulative rates were calculated using the 52-week mean population size. Standardized mortality rates were calculated, adjusting for age and sex with indirect standardization, as described in a previous report.¹ All analysis was performed using R version 4.1.0. The UCLA institutional review board deemed this study to be exempt.

By April 3, 2021, 394 066 COVID-19 cases and 2555 deaths due to COVID-19 had been reported among the US prison population (Table). The cumulative incidence rate per 100 000 persons was 30 780 cases for the prison population and 9350 cases for the US population, with a prison-to-US cumulative incidence ratio of 3.3 (95% CI, 3.3-3.3). The standardized mortality rate per 100 000 persons was 199.6 deaths for the prison population and 80.9 deaths for the US population (Table), with a prison-to-US standardized cumulative mortality rate ratio of 2.5 (95% CI, 2.3-2.7).

The prison population weekly incidence rate peaked during the week of December 13, 2020, when there were 2327 new cases per 100 000 persons. The standardized mortality rate peaked during the week of January 3, 2021, with 9.6 new deaths per 100 000 persons (Figure). During these weeks, the prison-to-US incidence rate ratio was 5.0 (95% CI, 5.0-5.1), while the standardized mortality ratio was 2.7 (95% CI, 1.9-3.8).

COVID-19 incidence and standardized mortality rates remained consistently higher among the prison population than the overall US population in the first year of the pandemic. While COVID-19 incidence and mortality rates peaked in late 2020 and early 2021 and have since declined, the cumulative toll of COVID-19 has been several times greater among the prison population than the overall US population.

A study limitation is reliance on publicly available data, which are subject to potential misreporting, delays,⁴ and inconsistencies in population estimates.³ In addition, differences in testing rates between the overall US population and the prison population may have biased incidence ratios. Also, the study period did not capture the more recent outbreak of COVID-19 cases due to the Delta variant. Nevertheless, this study underscores the importance of initiatives such as vaccination, decarceration, and continued disease surveillance in prison settings as long as the pandemic continues.

Corresponding Author: Neal Marquez, MPH, Los Angeles School of Law, UCLA Law COVID-19 Behind Bars Data Project, University of California, Los Angeles, 385 Charles E. Young Dr E, Los Angeles, CA 90095 (marquezn@law.ucla.edu).

Accepted for Publication: September 16, 2021.

Published Online: October 6, 2021. doi:10.1001/jama.2021.17575

Author Contributions: Mr Marquez had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Marquez, Ward, Parish, Saloner.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: Marquez, Ward.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Marquez, Saloner.

Obtained funding: Dolovich.

Administrative, technical, or material support: Parish.

Supervision: Dolovich.

Conflict of Interest Disclosures: Dr Saloner reported receiving personal fees from the University of Wisconsin and the Cambridge Health Alliance. No other disclosures were reported.

Funding/Support: Mr Marquez and Dr Dolovich were funded by the Vital Projects Fund and Arnold Ventures. Mr Marquez was funded by a National Institute of Child Health and Human Development (NICHD) P2C grant (P2C HD042828). Ms Ward was funded by a NICHD T32 grant (T32-HD 094687). Dr Saloner was funded by a Greenwall Foundation Making a Difference grant. Dr Dolovich was funded by a Centers for Disease Control and Prevention contract.

Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication.

Additional Contributions: We acknowledge assistance from the UCLA Law COVID Behind Bars Data Project, whose researchers supervised data collection.