CKD Among Top Chronic Conditions Linked to COVID-19 Hospitalization

New cross-sectional surveillance data from a 13-state, 98-county analysis show adults hospitalized with COVID-19 were disproportionately affected by chronic kidney disease (CKD), underscoring its continued association with severe outcomes in the later stages of the pandemic.1

These findings underscore the increased risk for severe COVID-19 outcomes in adults with CKD even in the later stages of the pandemic, when vaccine coverage and hybrid immunity were widespread.1

“For older adults and others at high risk of severe COVID-19 outcomes, these findings underscore the importance of staying up to date with recommended COVID-19 vaccines and seeking prompt outpatient antiviral treatment after a positive SARS-CoV-2 test result,” wrote study investigator Sarah Hamid, PhD, from the department of epidemiology at Emory University and colleagues.1

During the COVID-19 pandemic, chronic medical conditions were associated with increased hospitalization risk. By 2022, > 96% of US adults had immunity through vaccination, prior infection, or both, coinciding with substantially lower rates of COVID-19–associated hospitalizations and deaths in the general population. However, the risk for severe disease among vulnerable groups has persisted, and their association with hospitalization risk has not been well characterized.1,2

To address this gap in research, investigators conducted a cross-sectional analysis across 3 surveillance seasons (week 40 of 1 year through week 39 of the next), comparing chronic conditions reported in the nationwide Behavioral Risk Factor Surveillance System (BRFSS) with medical records from the COVID-19–Associated Hospitalization Surveillance Network (COVID-NET).1

Investigators included the following chronic conditions: asthma, chronic obstructive pulmonary disease (COPD), coronary artery disease (CAD), CKD, diabetes mellitus, history of stroke, non-severe obesity (body mass index [BMI] 30–39 kg/m²), severe obesity (BMI ≥40 kg/m²), and current smoking status.1

For each condition, hospitalization rates were stratified by age, sex, and race/ethnicity. To assess the combined effects of multimorbidity, investigators examined commonly co-occurring condition pairs, including diabetes and CAD, diabetes and CKD, and CKD and CAD.1

The 13-state analysis included 23,106 hospitalized, community-dwelling adults ≥ 18 years of age from California, Colorado, Connecticut, Georgia, Maryland, Michigan, Minnesota, New Mexico, New York, Ohio, Oregon, Tennessee, and Utah. Among those individuals, 69.3% had ≥1 of 8 chronic conditions.1

The eligibility criterion was restricted to patients who reported COVID-19-related illnesses as the primary reason for hospital admission. Those inhabiting congregate settings, such as long-term care facilities, at the time of hospitalization, were excluded.1

Upon analysis, investigators found that during the 2022–2023 surveillance season, 70.1% of adults hospitalized with COVID-19 were ≥ 65 years of age, compared with 22.2% of adults in the general population residing in COVID-NET states.1

The prevalence of chronic conditions in COVID-NET mirrored national estimates. However, adults hospitalized with COVID-19 had an increased prevalence of chronic medical conditions than community-dwelling adults in these states. The largest differences were observed for diabetes (35.2% vs 11.5%), CKD (24.5% vs 3.7%), coronary artery disease (23.4% vs 6.3%), chronic obstructive pulmonary disease (COPD) (17.9% vs 6.3%), and history of stroke (12.5% vs 3.3%).1

When compared with adults without chronic conditions, investigators reported that the adjusted rate ratios (aRRs) for COVID-19–associated hospitalization increased stepwise with comorbidity burden: 2.1 (95% Uncertainty Interval [UI], 1.7-2.5) for 1 condition, 4.0 (95% UI, 3.3-4.9) for 2 conditions, and 5.8 (95% UI, 4.7-7.1) for ≥3 conditions.1

Across individual conditions, aRRs ranged from 1.0 (95% CI, 0.8–1.2) for non-severe obesity to 4.5 (95% CI, 3.4–5.9) for CKD. CKD, diabetes mellitus, and CAD were associated with increased hospitalization risk across all age groups, with relative risks ranging from 1.6- to 8.8-fold, depending on age.1

Investigators also noted adults with both diabetes and CAD, diabetes and CKD, or CKD and CAD had increased rates of COVID-19–associated hospitalization than those with either condition alone.1

Across all surveillance seasons, adults with 1, 3, or ≥ 3 chronic conditions experienced increased COVID-19–associated hospitalization rates than adults with no chronic conditions. The proportion of hospitalizations involving ≥2 chronic conditions increased from 32.7% (95% CI, 30.7–34.8) in 2020–2021 to 44.9% (95% CI, 40.3–49.6) in 2022–2023.1

Between the 2020–2021 and 2022–2023 surveillance seasons, investigators called attention to the proportion of hospitalized adults with coronary artery disease increased from 13.6% (95% CI, 12.6–14.6) to 23.4% (95% CI, 21.1–25.9), history of stroke from 5.2% (95% CI, 4.6–5.9) to 12.5% (95% CI, 10.5–14.8), CKD from 15.3% (95% CI, 14.2–16.4) to 24.5% (95% CI, 22.2–27.0), and COPD from 10.3% (95% CI, 9.5–11.2) to 17.9% (95% CI, 15.9–20.1).1

In contrast, the proportion of hospitalized adults with non-severe obesity declined from 35.0% (95% CI, 33.7–36.3) to 24.2% (95% CI, 22.0–26.4), and severe obesity declined from 15.4% (95% CI, 14.4–16.4) to 7.9% (95% CI, 6.7–9.2) over the same period.1

“8 of 9 chronic conditions assessed were associated with increased risk of COVID-19 hospitalization; risk varied by condition and age. Older age was the strongest risk factor,” concluded investigators. “Findings can guide prevention and treatment by identifying populations at greatest risk of COVID-19 hospitalization.”1

References

1. Hamid S, Derado G, Pham H, et al. Chronic Conditions as Risk Factors for COVID-19–Associated Hospitalization Among Adults, 2020–2023. American Journal of Preventive Medicine. Published online December 2025:108227. doi:https://doi.org/10.1016/j.amepre.2025.108227

2. Jones JM, Irene Molina Manrique, Stone M, et al. Estimates of SARS-CoV-2 Seroprevalence and Incidence of Primary SARS-CoV-2 Infections Among Blood Donors, by COVID-19 Vaccination Status — United States, April 2021–September 2022. 2023;72(22):601-605. doi:https://doi.org/10.15585/mmwr.mm7222a3