COVID-19 and Excess All-Cause Mortality in the US and 20 Comparison Countries, June 2021-March 2022 (2024)

The US experienced high COVID-19 death rates and higher excess all-cause mortality compared with peer countries during 2020.¹ However, an important question is how cross-national differences in mortality shifted during 2021 and 2022 with both widespread availability of vaccination and new variants. We compared COVID-19 and excess all-cause mortality in the US, the 10 most- and least-vaccinated states, and 20 peer Organization for Economic Co-operation and Development (OECD) countries during the Delta and winter Omicron waves.

Using previous methodology, we compared the US overall, the 10 most- and least-vaccinated states, and the 20 OECD countries with 2021 population exceeding 5 million and greater than $25 000 per capita gross domestic product (Supplement 1).¹ US COVID-19 mortality, all-cause mortality, and vaccination data were obtained from the US Centers for Disease Control and Prevention.² For other countries, COVID-19 mortality data were obtained from the World Health Organization, all-cause mortality data from OECD databases, and vaccination data from Our World in Data (Supplement 1).^3-5 Some mortality data from 2021 and 2022 were provisional.

Each location’s COVID-19 mortality rate per capita was calculated over 2 periods: (1) Delta from June 27, 2021 (week 26), to December 25, 2021 (week 51), and (2) Omicron from December 26, 2021 (week 52), to March 26, 2022 (week 12). We estimated excess all-cause mortality by comparing mortality in each period with mortality in 2015-2019, fitting underlying trends using prepandemic, out-of-sample validation (Supplement 1).⁶

For each period, we calculated the difference in US deaths if mortality rates of other locations were realized. We used regression models to statistically compare rates across locations (Supplement 1), with significance set at P < .005 for 2-sided tests to account for multiple testing. Analyses were conducted in R version 4.0.2 (R Foundation for Statistical Computing). The study was deemed not human subjects research by the Brown University institutional review board.

The US reported 370 298 COVID-19 deaths (112 per 100 000) during the Delta and Omicron waves (61/100 000 and 51/100 000, respectively). COVID-19 deaths per capita in the US overall and in both state subgroups significantly exceeded those of all peer countries during the study period (Table 1). However, there were significantly fewer COVID-19 deaths in the top 10 states by vaccination uptake (73% coverage) at 75 deaths/100 000 compared with the bottom 10 (52% coverage) at 146 per 100 000 (P < .001).

US excess all-cause mortality exceeded COVID-19 mortality at 145/100 000 and exceeded peer countries in all periods, as did excess all-cause mortality in the least-vaccinated states (Table 2). However, the 10 most-vaccinated states had excess all-cause mortality comparable with or less than that of several peer countries over Delta and Omicron combined (eg, Denmark, Germany, the Netherlands, Austria, Italy, Finland). While excess all-cause mortality in the top 10 states significantly exceeded that of many comparators during Omicron, excess all-cause mortality was significantly less than COVID-19 mortality for the top 10 states during this wave (29 vs 47 per 100 000, P < .001).

From June 27, 2021, to March 26, 2022, the US would have averted 122 304 deaths if COVID-19 mortality matched that of the 10 most-vaccinated states and 266 700 deaths if US excess all-cause mortality rate matched that of the 10 most-vaccinated states. If the US matched the rates of other peer countries, averted deaths would have been substantially higher in most cases (range, 154 622-357 899 for COVID-19 mortality; 209 924-465 747 for all-cause mortality).

The US continued to experience significantly higher COVID-19 and excess all-cause mortality compared with peer countries during 2021 and early 2022, a difference accounting for 150 000 to 470 000 deaths. This difference was muted in the 10 states with highest vaccination coverage; remaining gaps may be explained by greater vaccination uptake in peer countries, better vaccination targeting to older age groups, and differences in health and social infrastructure.

This study also highlights the value of excess mortality in understanding effects of COVID-19. Excess all-cause mortality began to fall below COVID-19 mortality in several countries and highly vaccinated states during Omicron, perhaps owing to reductions in non–COVID-19 deaths. However, cross-location differences may also reflect differences in COVID-19 death coding.

Limitations include use of some provisional mortality estimates and lack of adjustment by age and comorbidities. Nevertheless, unadjusted estimates remain important, because a country’s response to COVID-19 should reflect risks in its population rather than a hypothetical standardized population.

These findings highlight that the US continued to lag peer countries in COVID-19 and excess all-cause mortality, albeit with lower mortality in highly vaccinated states.

Section Editors: Jody W. Zylke, MD, Deputy Editor; Kristin Walter, MD, Senior Editor.

Accepted for Publication: November 7, 2022.

Published Online: November 18, 2022. doi:10.1001/jama.2022.21795

Corresponding Author: Alyssa Bilinski, PhD, Department of Health Services, Policy, and Practice, Brown School of Public Health, 121 S Main St, Office 828, Providence, RI 02903 (alyssa_bilinski@brown.edu).

Author Contributions: Dr Bilinski 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: Bilinski, Emanuel.

Acquisition, analysis, or interpretation of data: Bilinski, Thompson.

Drafting of the manuscript: All authors.

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

Statistical analysis: Bilinski, Thompson.

Conflict of Interest Disclosures: Dr Bilinski reported receiving grants from the Centers for Disease Control and Prevention though the Council of State and Territorial Epidemiologists (NU38OT000297). Dr Emanuel reported serving as a paid or unpaid speaker for United Health Group, Blue Cross Blue Shield Dana Point, Center for Global Development, CBI/Informa, American Academy of Arts and Sciences, University of California San Francisco, UCSF Medicine Grand Rounds, Vagelos College of Physicians & Surgeons, UNESCO, NCCN Academy for Excellence & Leadership, National Institutes of Health, ASPO, NCAC BC/BS, Penn-Cellicon Valley 2021, Activity Based Funding Conference, Leonard Davis Institute, Penn Medical Alumni Weekend, National Health Equity Summit, The Galien Foundation, Temple Shalom Chicago, Perry World House Graduate Association, AIFA-Italian Medicine Agency, Penn Rising Scholar Success Academy, Rainbow Push Coalition, Infectious Diseases Society of America, Rise Health, VinFuture, Wellsky, Brown University Warren Alpert Medical School, 19th Annual Signature Foundation Health Policy Forum, Healthcare Leaders of New York, 21st Population Health Colloquium, MedImpact, Village MD, University of Syndney, Massachusetts Association of Health Plans, Virta Health, Tel Aviv University, American Philosophical Society, Princeton University, Philadelphia Committee on Foreign Relations, Health Action Alliance, Yale University, Hartford Medical Society, American Board of Pediatric Dentistry, Mt Sinai Ichan School of Medicine, Perelman School of Medicine, University of Minnesota, Institute for Health and Productivity Studies, Association of Academic Health Centers, Hawaii Medical Service Association and Queen’s Health System, University of Pennsylvania, and Macalester College; serving as a paid or unpaid panelist for World Affairs Council, Rightway, and the Organisation for Economic Co-operation and Development; receiving travel reimbursem*nt from Blue Cross Blue Shield Dana Point, Hartford Medical Society, Association of Academic Health Centers, Macalester College, and Oak HC/FT; serving as a paid or unpaid board member for Village MD and Oncology Analytics; serving on the advisory board of Cellares, Village MD, HIEx Health Innovation Exchange, Colton Center for Autoimmunity, JSL Health, World Health Organization COVID-19 Ethics and Governance Working Group, and Biden Transition COVID-19 Committee; serving as special advisor to the World Health Organization director general; and that he is a venture partner at Oak HC/FT and a partner at Embedded Healthcare LLC and COVID-19 Recovery Consulting. No other disclosures were reported.

Funding/Support: This study was partially funded by the Centers for Disease Control and Prevention (CDC) though the Council of State and Territorial Epidemiologists (NU38OT000297-02, Dr Bilinski) and Colton Foundation (Dr Emanuel).

Role of the Funder/Sponsor: The CDC 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; and decision to submit the manuscript for publication.

Data Sharing Statement: See Supplement 2.

Additional Contributions: We gratefully acknowledge research assistance from Alexandra Norris, AM (Brown University). Ms Norris received compensation from grant NU38OT000297-02.