Incident CKD After Hospitalization for COVID-19

Results of previous studies have suggested an association between COVID-19 and accelerated decline in estimated glomerular filtration rate (eGFR) in hospitalized patients. However, according to Spencer Krichevsky and colleagues, those studies were limited by cohort size, duration of follow-up, and geo-specificity. There is also a lack of data on characterization of incident chronic kidney disease (CKD) in nonhospitalized patients with CKD.

The researchers conducted an analysis of electronic health record data from 77 health systems in the United States in the National COVID Cohort Collaborative. They reported results of the analysis during a poster session at the American Society of Nephrology Kidney Week 2023 in a poster titled Risk Factors for Post-COVID-19 Incident CKD in the National COVID Cohort Collaborative.

The analysis included data on adults diagnosed with COVID-19 between March 1, 2020, and October 1, 2022, without pre-COVID-19 CKD. The cohort was evaluated for post-COVID-19 CKD through December 31, 2022. Diagnosis codes or outpatient eGFR measurements were used to identify CKD.

Risk factors were analyzed using multivariable models. Risk factors of interest were demographics (age, sex, race/ethnicity), geographical region (Midwest, Northeast, South, West), hospitalization, acute kidney injury (AKI), and a reported diagnosis of long COVID-19.

Of 3.7 million patients, 2% (n=76,000) had incident post-COVID-19 CKD. Of those, 73% (n=55,000) were not assigned a CKD diagnosis code but met requirements for eGFR-based CKD. In multivariable models, there were associations between incident CKD and older age, male sex, and Black of Native Hawaiian or Pacific Islander race (compared with White race).

The event rates for incident CKD for patients hospitalized during the COVID-19 diagnosis were significantly higher than among those never hospitalized for COVID-19 (11.4 vs 28.7 per 1000 patient-years). Among hospitalized patients, those with AKI (vs no AKI) had an even higher rate of incident CKD (98.3 vs 21.2 per 1000 patient-years).

In multivariable analyses, when compared with patients who were never hospitalized with COVID-19, the incidence of CKD was much higher in those who were hospitalized and developed AKI (hazard ratio [HR], 3.82; P<.001). Compared with the Midwest, the adjusted odds ratios for incident CKD were higher in the West (1.32; P<.001) and South (1.03; P<.001) and lower in the Northeast (0.94; P<.001).

In a subcohort of 1.5 million patients evaluated at U09.9-reporting sites, there was an association between long COVID-19 and a moderately higher HR for incident CKD (1.14; P<.001).

In conclusion, the researchers said, “In one of the largest studies on this topic, we observe that incident CKD in patients with COVID was underdiagnosed and influenced by geographical region, hospitalizations, and AKI. Patients with long COVID had higher rates of CKD compared with those without.”

Source: Krichevsky S, Koraishy FM, Ellison DH. Risk factors for post-COVID-19 incident CKD in the National COVID Cohort Collaborative. TH-PO112. Abstract of a poster presented at the American Society of Nephrology Kidney Week 2023; November 2, 2023; Philadelphia, Pennsylvania.