Importance Since 2020, COVID-19 has dramatically impacted the US population and health care system. Reporting requirements, circulating variants, testing practices, and population immunity from vaccination and previous infections evolved as the COVID-19 pandemic progressed. Evidence-based public health policy and resource allocation decisions require current estimates of disease burden. Objective To estimate the age group-specific burden of COVID-19–associated illnesses, outpatient visits, hospitalizations, and deaths in the US from October 2022 to September 2024. Design, Setting, and Participants In this cross-sectional study, hierarchical Bayesian modeling, adjusting for underdetection of SARS-CoV-2 due to testing practices and test sensitivity, was applied to hospitalization data from the population-based COVID-19 Hospitalization Surveillance Network (COVID-NET) database, which includes 89 counties and jurisdictional equivalents in 12 states covering approximately 10% of the US population. Data from 94 363 participants from October 2022 to September 2023 (surveillance period, 2022-2023) and from 72 176 participants from October 2023 to September 2024 (surveillance period, 2023-2024) were included, and probabilistic mathematical multiplier models estimated counts of deaths, outpatient visits, and symptomatic illnesses incorporating literature and study-based multipliers. Data were modeled from April 2024 to September 2025. Exposures COVID-NET patients with a laboratory-confirmed COVID-19–associated hospitalization, defined as a positive SARS-CoV-2 test result within 14 days before or during hospitalization. Main Outcomes and Measures Estimated national counts with 95% uncertainty intervals (UIs) of outpatient visits, illnesses, hospitalizations, and deaths by age group. Results In 2022-2023, there were an estimated 43.6 million (95% UI, 25.3-64.0 million) COVID-19–associated illnesses, 10.0 million (95% UI, 7.0-13.1 million) outpatient visits, 1.1 million (95% UI, 0.9-1.4 million) hospitalizations, and 101 300 (95% UI, 73 600-132 500) deaths. In 2023-2024, there were an estimated 33.0 million (95% UI, 20.2-49.0 million) COVID-19–associated illnesses, 7.7 million (95% UI, 5.5-9.9 million) outpatient visits, 879 100 (95% UI, 738 600-1 039 000) hospitalizations, and 100 800 (95% UI, 64 000-140 400) deaths. In 2023-2024, people 65 years and older comprised 17.7% of the total US population but accounted for 47.9% (95% UI, 27.1-66.9) of COVID-19–associated illnesses, 64.3% (95% UI, 53.1-73.4) of outpatient visits, 67.6% (95% UI, 65.9-69.2) of hospitalizations, and 81.2% (95% UI, 70.2-90.6) of deaths. Conclusions and Relevance In this cross-sectional study, despite declining from the first to the second surveillance period, the COVID-19 burden continued to have a large impact in the US, particularly among adults 65 years and older, underscoring the ongoing importance of prevention measures.
Koumans et al. (2026) studied this question.