Association Between Red Cell Distribution Width and Mortality in Patients with Klebsiella pneumoniae Bloodstream Infection: A Cohort Study

Yingxiu Huang, Ting Ao, Ming Hu, Peng Zhen Department of Infectious Disease, Beijing Luhe Hospital, Capital Medical University, Beijing, 101149, People’s Republic of ChinaCorrespondence: Peng Zhen, Department of Infectious Disease, Beijing Luhe Hospital, Capital Medical University, No. 82 Xinhua South Road, Tongzhou District, Beijing, 101149, People’s Republic of China, Email [email protected]: Despite red blood cell distribution width (RDW) is a routinely available hematological data and has been found to be associated with mortality in different diseases, the specific association of RDW on Klebsiella pneumoniae bloodstream infection (KP-BSI) outcome remains underexplored.Methods: This retrospective cohort study investigates the association between RDW levels and in-hospital mortality in 267 adult patients with KP-BSI admitted to a tertiary hospital between 2019 and 2024. RDW was analyzed both as a continuous variable and categorized into tertiles. The primary outcome was in-hospital mortality. Multivariable logistic regression, subgroup analyses, and sensitivity analyses were systematically employed to investigate the association between RDW levels and mortality risk. Receiver operator characteristic (ROC) curve analysis was performed to evaluate the prognostic value of RDW for in-hospital mortality in KP-BSI.Results: During hospitalization, 122 mortality events were recorded, constituting 45.7% of the study population (n=267). When RDW was examined as a continuous factor, a significant positive relationship was observed between RDW and mortality in the full adjusted model, the odds ratio (OR) was 1.05 (95% confidence interval [CI] (1.02~1.08), P=0.003). As RDW tertiles elevated, the incidence of mortality increased, with the OR for T3 (> 50.8fL) group being higher than that for T1 (< 43.2fL) group (OR: 7.63, 95% CI: 2.96– 19.69; p< 0.001) in Model 3. Subgroup and sensitivity analyses remain consistent. ROC analysis showed that RDW predicted in-hospital mortality with an AUC of 0.705.Conclusion: High RDW values were independently associated with an increased risk of in-hospital mortality in patients with KP-BSI, indicating their potential utility as for prognostic assessment.Keywords: red cell distribution width, RDW, bloodstream infection, Klebsiella pneumoniae, mortality