Figure 1.

Flow chart illustrating the methodology followed to establish the study cohort. The cohort of 126 patients constitutes an arbitrary sample obtained from a pool of 478 patients with coronavirus disease 2019 at risk for AKI during the study period. Because of limited availability of the research personnel, 352 specimens were discarded by the central laboratory without undergoing screening. By virtue of their disease state, patients with kidney failure on long-term dialysis were not at risk for AKI and thus were excluded. Patients with kidney transplantation were also excluded to minimize confounding factors. SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.