A Practical Nomogram Based on RDW-CV for Predicting Clinical Outcome in Elderly Septic Patients.

Objective: The retrospective study established a prognostic nomogram based on red blood cell distribution width-coefficient of variation (RDW-CV) for elderly septic patients.

Methods: We analyzed 1997 critically ill patients admitted between December 2016 and June 2019, and 986 elderly septic patients were included in the study and stratified into survival and non-survival groups. Using machine learning-based feature importance analysis and multivariate logistic regression, we evaluated predictors of mortality in the elderly septic patients, with particular focus on RDW-CV. We constructed a nomogram incorporating RDW-CV to predict clinical outcomes in elderly septic patients and evaluated its performance.

Results: The mortality of 986 elderly sepsis patients was 27.48%. Importance analysis showed that RDW-CV demonstrated superior predictive value for mortality. The RDW-CV (17.22 ±3.98%) in the non-survival group was significantly higher than that (15.30 ±2.81%) in the survival group, p < 0.0001. The RDW-CV was used to predict the mortality of patients and the AUC was 0.65 (95% CI: 0.61, 0.69). Multivariate logistic regression showed that mechanical ventilation, drug-resistant bacterial infection, hemofiltration, and RDW-CV independently influenced mortality, a predictive nomogram was developed based on a final model that included RDW-CV and other clinical indicators, the area under the curve (AUC) was found to be 0.755 (95% CI: 0.714, 0.797), decision curve analyses (DCA) revealed superior net benefit of the nomogram across threshold probabilities of 0.30-1.00 in both derivation and validation cohorts. The calibration curve demonstrates strong agreement between the model's predicted probabilities and the validation cohort's predicted probabilities.

Conclusion: Higher RDW-CV was found to have a significant association with mortality prediction, the nomogram based on RDW-CV with other clinical indicators could more accurately predict the clinical outcome of elderly septic patients, validation analysis confirmed the accuracy of the nomogram, the predictive model offered clinical applicability.