Association of Kidney Function with Sepsis-Related Mortality

Background: Although chronic kidney disease (CKD) has been associated with mortality in sepsis, literature describing outcomes of sepsis among patients with CKD have reported inconsistent results. We conducted a population-based study to better characterize the outcomes of hospital admissions for sepsis among patients with and without CKD in the United States. We hypothesized that the presence and severity of CKD would be associated with higher risks of mortality and prolonged hospital stay. Methods: We identified hospitalizations for patients 18 years or older with sepsis or septic shock using the National Inpatient Sample (NIS), an all-payor database containing discharge level data from a 20% stratified sample of discharges from non-VA and non-rehabilitation hospitals in the United States. Sepsis and septic shock, CKD-3, CKD-4/5, and ESKD were identified using International Classification of Diseases, 9th and 10th Revision diagnosis codes. We used logistic regression to determine the odds of mortality and prolonged hospital stay by the presence and severity of CKD, adjusted for patient demographics, comorbidity and severity of illness, geographic region, and hospital characteristics. Results: We found 20,870,713 admissions in adult patients with sepsis or septic shock from 2010 to 2019. Of these 15,476,852 (74.2%) had normal or near normal kidney function, 3,378,657 (16.2%) had CKD3, 547,172 (2.6%) had CKD4/5, and 1,468,032 (7.0%) had ESKD. Sepsis- and septic shock-associated in-hospital mortality rates for patients with normal or near normal kidney function, CKD-3, CKD-4/5, and ESKD were 11.6%, 13.7%, 16.3%, and 17.9%, respectively. Figure 1 shows adjusted odds of mortality and prolonged hospital stay for CKD stages relative to patients with normal or near normal kidney function. Conclusion: In this population-based study of admissions involving sepsis and septic shock in the United States, presence and severity of CKD were associated with higher adjusted odds of in-hospital mortality and prolonged hospital stay.