A population-based study would be useful to identify the association between chronic kidney disease (CKD) or acute kidney injury (AKI) and prognosis of coronavirus disease 2019 (COVID-19) patients. This retrospective study utilized the claim data from Korea. Patients who underwent COVID-19 testing and were confirmed to be positive were included and divided into the following three groups based on the presence of CKD or requirement of maintenance dialysis: Non-CKD (participants without CKD), non-dialysis CKD (ND-CKD), and dialysis-dependent CKD (DD-CKD) patients. We collected data on the development of severe clinical outcomes and death during follow-up. Severe clinical outcomes were defined as the use of inotropics, conventional oxygen therapy, high-flow nasal cannula, mechanical ventilation, or extracorporeal membrane oxygenation and the development of AKI, cardiac arrest, myocardial infarction, or acute heart failure after the diagnosis of COVID-19. AKI was defined as the initiation of renal replacement therapy after the diagnosis of COVID-19 in patients not requiring maintenance dialysis. Death was evaluated according to survival at the end of follow-up. Altogether, 7,341 patients were included. The median duration of data collection was 19 (interquartile range, 11-28) days. On multivariate analyses, odds ratio (OR) for severe clinical outcomes in the ND-CKD group was 0.88 (95% confidence interval [CI], 0.64-1.20; P = 0.422) compared to the Non-CKD group. The DD-CKD group had ORs of 7.32 (95% CI, 2.14-33.90; P = 0.004) and 8.32 (95% CI, 2.37-39.21; P = 0.002) compared to the Non-CKD and ND-CKD groups, respectively. Hazard ratio (HR) for death in the ND-CKD group was 0.79 (95% CI, 0.49-1.26; P = 0.318) compared to the Non-CKD group. The DD-CKD group had HRs of 2.96 (95% CI, 1.09-8.06; P = 0.033) and 3.77 (95% CI, 1.29-11.06; P = 0.016) compared to the Non-CKD and ND-CKD groups, respectively. DD-CKD alone was associated with severe clinical outcomes and higher mortality. There was no significant difference in frequency of severe clinical outcomes or mortality rates between the Non-CKD and ND-CKD groups. In patients not requiring maintenance dialysis, AKI was associated with old age, male sex, and high Charlson's comorbidity index score but not with the presence of CKD. HRs for patients with AKI were 11.26 (95% CI, 7.26-17.45; P < 0.001) compared to those for patients without AKI in the multivariate analysis. AKI was associated with severe clinical outcomes and patient survival, rather than underlying CKD. CKD requiring dialysis is associated with severe clinical outcomes and mortality in patients with COVID-19; however, the development of AKI is more strongly associated with severe clinical outcomes and mortality.

Choi JY, et al. J Korean Med Sci. 2018 Jan;33(9):e74. https://doi.org/10.3346/jkms.2018.33.e74

Background: This study aimed to evaluate the association between sex and clinical outcomes in patients with coronavirus disease (COVID-19) using a population-based dataset. Methods: In this retrospective study, insurance claims data from the Korea database were used. Patients who tested positive for COVID-19 were included in the study. All diseases were defined according to the International Classification of Diseases 10th revision. During follow-up, the clinical outcomes, except mortality, were assessed using the electrical codes from the dataset. The clinical outcomes noted were: hospitalization, the use of inotropics, high flow nasal cannula, conventional oxygen therapy, mechanical ventilation, extracorporeal membrane oxygenation, development of acute kidney injury, cardiac arrest, myocardial infarction, acute heart failure, pulmonary embolism, and disseminated intravascular coagulation after the diagnosis of COVID-19. Results: A total of 7327 patients were included; of these, 2964 patients (40.5%) were men and 4363 patients (59.5%) were women. There were no significant differences in the Charlson comorbidity index score between men and women in the same age group. The incidence of mortality and clinical outcomes was higher among men than among women. The mortality rate was the highest for the populations aged 50–64 or ≥65 years. The subgroup analyses for age, diabetes mellitus, or hypertension showed favorable results for patient survival or clinical outcomes for women compared to men. Conclusion: Our population-based study showed that female patients with COVID-19 were associated with favorable outcomes. Furthermore, the impact of sex was more evident in patients aged 50–64 or ≥65 years.

Seok Hui Kang, Sang Woon Kim, Keuk Jun Kim, Kyu Hyang Cho, Jong Won Park, Chan-Duck Kim, Jun Young Do. Kidney Research and Clinical Practice 2019;38:472-80. https://doi.org/10.23876/j.krcp.19.049