COVID-19 Hospitalisation Tied to Higher Kidney Failure Risk

TOPLINE:

Patients with COVID-19 who required hospitalisation had a more than sevenfold higher risk for kidney failure than individuals without the condition, with this elevated risk persisting beyond 180 days. No elevated risk was observed among non-hospitalised patients.

METHODOLOGY:

• Researchers conducted a population-based cohort study using linked primary and secondary care data from England through the OpenSAFELY platform to assess the long-term risk for kidney failure following COVID-19.
• They included 3,544,310 patients (median age, 44 years; 53.2% women) with COVID-19 and 10,031,535 matched individuals without COVID-19; 6.9% of patients with COVID-19 were hospitalised.
• Participants without preexisting kidney failure (initiation of dialysis or kidney transplant or estimated glomerular filtration rate [eGFR] < 15 mL/min/1.73 m²) and with at least 3 months of prior follow-up were included.
• The median follow-up duration was 446 days for patients with COVID-19 and 410 days for matched individuals. Follow-up started from 28 days after the diagnosis of COVID-19.
• The primary outcome was the time to kidney failure; secondary outcomes were a 50% reduction in the eGFR and all-cause death.

TAKEAWAY:

• Patients hospitalised with COVID-19 had a more than sevenfold higher risk for kidney failure than matched control individuals (adjusted hazard ratio [aHR], 7.74; 95% CI, 7.00-8.56), with the risk persisting beyond 180 days of follow-up; the risks for kidney failure were particularly pronounced among those admitted to the ICU or with acute kidney injury during hospitalisation.
• COVID-19 requiring hospitalisation was also significantly associated with increased risks for a 50% reduction in the eGFR (aHR, 3.49; 95% CI, 3.25-3.75) and death (aHR, 4.93; 95% CI, 4.83-5.04).
• No increased risk for kidney failure was found among non-hospitalised patients (aHR, 0.85; 95% CI, 0.79-0.90).
• Black ethnic groups faced significantly higher risks for kidney failure than White or South Asian ethnic groups.

IN PRACTICE:

“Our results suggest that interventions to minimise the risk of severe COVID-19 should continue to be optimised among vulnerable groups, and that kidney function should be proactively monitored after discharge,” the authors wrote.

SOURCE:

This study was led by Viyaasan Mahalingasivam, London School of Hygiene & Tropical Medicine, London, England. It was published online on June 18, 2025, in The Lancet Regional Health – Europe.

LIMITATIONS:

The removal of higher-risk individuals from the non-hospitalised group may have led to an underestimation of the risk for kidney outcomes in this group compared with non-infected comparators. Detecting a 50% reduction in the eGFR relied on regular blood tests, which were more common in patients with chronic health conditions and may have inflated observed risks due to more frequent monitoring. Additionally, some important covariates, such as occupation and type of vaccination, were not included in the analysis.

DISCLOSURES:

This study was funded through a Career Development Award from the National Institute for Health and Care Research. Some authors reported receiving research grants or funding, travel grants, awards, reimbursements, fellowships, honoraria, and consulting fees and having other ties with several pharmaceutical companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.