COVID-19 and Kidney Disease (KD): A Retrospective Investigation in a Rural Southwestern Missouri Region Patient Population.

Background: Studies have linked pre-existing kidney disease (KD) to higher rates of mortality due to coronavirus disease 2019 (COVID-19) infection. In the rural Midwest, where KD is prevalent, the impact of COVID-19 has been significant in a population that includes many patients on Medicare or Medicaid.

Methods: A retrospective cohort study was performed assessing patients with acute kidney injury (AKI), chronic kidney disease (CKD) and end stage renal disease (ESRD), with and without COVID-19. International Classification of Diseases 10 Revision codes were submitted by physicians into Freeman Health System's Electronic Medical Records and gathered from April 2020 to January 2021. The data were analyzed and compared to determine whether the mortality rate in patients with varying stages of KD and COVID-19 was higher than the mortality rate in patients with KD alone, excluding variables such as sex and age.

Results: The 95% confidence interval (CI) of the mortality rate of patients with COVID-19 and any degree of KD, encompassing both AKI and CKD, was between 30.21% and 37.63%. This metric was significantly higher than the 95% CI of COVID-19 infection (6.70%-9.96%, p<0.0001) or KD alone (10.89%-13.01%, p<0.0001). Within those with COVID-19 and KD, the highest rate of mortality was in patients with AKI (38.13% and 49.02%). There was not sufficient statistical support in our sample to assert that COVID-19 increased mortality in ESRD patients.

Conclusions: Based on our results, patients with KD and COVID-19 are at higher risk for mortality when compared to patients with KD alone. Further studies are warranted into individual comorbidities affecting KD patient outcomes with COVID-19.