How age and underlying conditions affect incidence of hospitalization and death after documented COVID-19 diagnosis among individuals aged >=20 years, a retrospective cohort study using PCORnet, April 2022 to March 2025
- 1Centers for Disease Control and Prevention
Abstract
BackgroundCOVID-19 vaccinations, therapeutics, and immunity from infection have reduced COVID-19 severity. It is unknown to what extent previously identified risk factors - age and underlying medical conditions (UC)--remain associated with severe COVID-19 incidence.
MethodsUsing electronic health record (EHR) data from PCORnet, we identified individuals aged [≥]20 years with COVID-19 during April 2022-March 2025. We used Poisson regression with cluster-robust sandwich standard errors to estimate adjusted cumulative incidence (aCI) and aCI ratios (aCIR) for hospitalization within 16 days and mortality within 30 days of COVID-19 diagnosis to estimate the association of UCs and UC categories, comparing those with an UC to those without (adjusted for sociodemographic and health characteristics). We examined aCI and aCIR for cancer, cardiac, hepatic, immunosuppression, metabolic, neurologic, pulmonary, renal, psychiatric, and other conditions by age groups: 20-49, 50-64, 65-79, and 80+ years.
ResultsAmong 1,662,679 patients with COVID-19, the cumulative incidence of hospitalization (4.7%, 6.3%, 10.8%, 22.6%) and mortality (0.11%, 0.42%, 1.0%, 3.6%) increased across the 20-49, 50-64, 65-79, and 80+ year old age groups, respectively. Within each age group, aCI for hospitalization and mortality increased with number of UCs, with the highest aCI among those with 3 or more UCs. aCIR by age group demonstrated that UCs, especially 2 or more, were associated with incidence of both outcomes in all age groups.
ConclusionSince 2022, older age has remained strongly associated with hospitalization and mortality after COVID-19 diagnosis. Adults with two or more UCs generally had higher incidence of both outcomes across age groups.
summarySince 2022, older age has remained strongly associated with hospitalization and mortality with COVID-19. Having two or more of certain underlying conditions is associated with these outcomes among adults younger than 65 years.
Related
- Three-year longitudinal safety surveillance following COVID-19 vaccination in individuals with underlying medical conditions
- Clinical Characteristics of Herpes Zoster Developing During Hospitalization Across Underlying Disease Groups: A Single-Center Retrospective Cohort Study
- Clinical Characteristics and Management of Pediatric Facial Wounds with Documented Infection or Delayed Presentation: A 25-Year Retrospective Case Series
- Changes in hepatic functional reserve and renal function during hospitalization in patients with chronic liver disease : A retrospective observational study of inpatient rehabilitation
- Calcium oxalate kidney stone morphology reflects underlying metabolic and clinical conditions
BibTeX
@misc{koumans2026underlying,
title = {{How age and underlying conditions affect incidence of hospitalization and death after documented COVID-19 diagnosis among individuals aged >=20 years, a retrospective cohort study using PCORnet, April 2022 to March 2025}},
author = {E. H. Koumans and G. Derado and M. M. Shah and N. Graff and C. Draper and S. Saydah and M. Briggs-Hagen and J. Denson and M. D. Kappelman and D. Thacker and E. J. Schenck and K. Nagavedu and T. K. Boehmer and D. Emerton and T. Carton and P. Patel and J. P. Block and PCORnet Network Partners},
howpublished = {medRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.18.26363440},
url = {https://www.medrxiv.org/content/10.64898/2026.09.18.26363440v1},
note = {CC BY-ND},
}
RIS
TY - UNPB
TI - How age and underlying conditions affect incidence of hospitalization and death after documented COVID-19 diagnosis among individuals aged >=20 years, a retrospective cohort study using PCORnet, April 2022 to March 2025
AU - E. H. Koumans
AU - G. Derado
AU - M. M. Shah
AU - N. Graff
AU - C. Draper
AU - S. Saydah
AU - M. Briggs-Hagen
AU - J. Denson
AU - M. D. Kappelman
AU - D. Thacker
AU - E. J. Schenck
AU - K. Nagavedu
AU - T. K. Boehmer
AU - D. Emerton
AU - T. Carton
AU - P. Patel
AU - J. P. Block
AU - PCORnet Network Partners
PY - 2026
DA - 2026/09/18
PB - medRxiv
DO - 10.64898/2026.09.18.26363440
UR - https://www.medrxiv.org/content/10.64898/2026.09.18.26363440v1
AB - BackgroundCOVID-19 vaccinations, therapeutics, and immunity from infection have reduced COVID-19 severity. It is unknown to what extent previously identified risk factors - age and underlying medical conditions (UC)--remain associated with severe COVID-19 incidence. MethodsUsing electronic health record (EHR) data from PCORnet, we identified individuals aged [≥]20 years with COVID-19 during April 2022-March 2025. We used Poisson regression with cluster-robust sandwich standard errors to estimate adjusted cumulative incidence (aCI) and aCI ratios (aCIR) for hospitalization within 16 days and mortality within 30 days of COVID-19 diagnosis to estimate the association of UCs and UC categories, comparing those with an UC to those without (adjusted for sociodemographic and health characteristics). We examined aCI and aCIR for cancer, cardiac, hepatic, immunosuppression, metabolic, neurologic, pulmonary, renal, psychiatric, and other conditions by age groups: 20-49, 50-64, 65-79, and 80+ years. ResultsAmong 1,662,679 patients with COVID-19, the cumulative incidence of hospitalization (4.7%, 6.3%, 10.8%, 22.6%) and mortality (0.11%, 0.42%, 1.0%, 3.6%) increased across the 20-49, 50-64, 65-79, and 80+ year old age groups, respectively. Within each age group, aCI for hospitalization and mortality increased with number of UCs, with the highest aCI among those with 3 or more UCs. aCIR by age group demonstrated that UCs, especially 2 or more, were associated with incidence of both outcomes in all age groups. ConclusionSince 2022, older age has remained strongly associated with hospitalization and mortality after COVID-19 diagnosis. Adults with two or more UCs generally had higher incidence of both outcomes across age groups. summarySince 2022, older age has remained strongly associated with hospitalization and mortality with COVID-19. Having two or more of certain underlying conditions is associated with these outcomes among adults younger than 65 years.
ER -