Pre-existing chronic kidney disease (CDK) was not associated with a severe clinical outcome of hospitalized COVID-19: results of a case-control study in Southern Italy

Abstract

The presence of co-morbidities is associated with a poor outcome in patients with COVID-19. The aim of the present study was to investigate the outcomes of patients with SARS-CoV-2 infection and chronic kidney disease (CKD) in order to assess its impact on mortality and severity of disease. We performed a multicenter, observational, 1:2 matched case-control study involving seventeen COVID-19 Units in southern Italy. All the adults hospitalized for SARS-CoV-2 infection and with pre-existing CKD were included (Cases). For each Case, two patients without CKD pair matched for gender, age (+5 years), and number of co-morbidities (excluding CKD) were enrolled (Controls). Of the 2,005 patients with SARS-CoV-2 infection followed during the study period, 146 patients with CKD and 292 patients without were enrolled in the case and control groups, respectively. Between the Case and Control groups, there were no statistically significant differences in the prevalence of moderate (17.1% vs 17.8%, p=0.27) or severe (18.8% and 13.7%, p=0.27) clinical presentation of COVID-19 or deaths (20.9% vs 28.1%, p=0.27). In the Case group, the patients dead during hospitalization were statistically higher in the 89 patients with CKD stage 4-5 compared to 45 patients with stages 1-3 CKD (30.3% vs 13.3%, p=0.03). Our data suggests that only CKD stage 4-5 on admission was associated with an increased risk of in-hospital death.

Keywords: COVID-19; Chronic kidney disease; SARS-CoV-2 infection; mortality; severity of disease.

Figure 1

Flow chart of patients enrolled in the study.

Figure 2

Clinical outcomes in different groups of patients.