Comparison of Acute Kidney Injury in Patients with COVID-19 and Other Respiratory Infections: A Prospective Cohort Study.

Previous studies have indicated an association between coronavirus disease 2019 (COVID-19) and acute kidney injury (AKI) but lacked a control group. The prospective observational COronaVIrus-surviVAl (COVIVA) study performed at the University Hospital, Basel, Switzerland consecutively enrolled patients with symptoms suggestive of COVID-19. We compared patients who tested positive for SARS-CoV-2 with patients who tested negative but with an adjudicated diagnosis of a respiratory tract infection, including pneumonia. The primary outcome measure was death at 30 days, and the secondary outcomes were AKI incidence and a composite endpoint of death, intensive care treatment or rehospitalization at 30 days. Five hundred and seven patients were diagnosed with respiratory tract infections, and of those, 183 (36%) had a positive PCR swab test for SARS-CoV-2. The incidence of AKI was higher in patients with COVID-19 (30% versus 12%, p < 0.001), more severe (KDIGO stage 3, 22% versus 13%, p = 0.009) and more often required renal replacement therapy (4.4% versus 0.93%; p = 0.03). The risk of 30-day mortality and a composite endpoint was higher in patients with COVID-19-associated AKI (adjusted hazard ratio (aHR) mortality 3.98, 95% confidence interval (CI) 1.10-14.46, p = 0.036; composite endpoint aHR 1.84, 95% CI 1.02-3.31, p = 0.042). The mortality risk was attenuated when adjusting for disease severity (aHR 3.60, 95% CI 0.93-13.96, p = 0.062). AKI occurs more frequently and with a higher severity in patients with COVID-19 and is associated with worse outcomes.