Red blood cell distribution width predicts in-hospital mortality in patients with a primary diagnosis of seizures in the ICU: a retrospective database study

Purpose The aim of this study was to determine the predictive value of red blood cell distribution width (RDW) in patients with a primary diagnosis of seizures admitted to the intensive care unit (ICU) in terms of in-hospital mortality. Methods This was a retrospective study of the eICU Collaborative Research Database of adult patients (aged 18-88 years) with a primary diagnosis of seizures in 2014 and 2015. The prognostic value of RDW was investigated using a receiver operating characteristic (ROC) curve, multiple logistic regression model, and net reclassification index (NRI). Results We identified 1568 patients who met the inclusion criteria. High RDW was significantly correlated with in-hospital mortality after adjusting for potential confounders with an odds ratio (OR) of 3.513 (95% confidence interval [CI]:1.699-7.266). The area under the ROC curve of RDW for in-hospital mortality was 0.7225. Compared with the prediction of in-hospital mortality using APACHE IV score alone, the continuous NRI with the RDW variable was 0.3507 (95%CI: 0.0584-0.6431, p < 0.05). The length of stay in the ICU of patients with an RDW >14.65% was significantly increased compared to those with normal RDW (log-rank test, p < 0.0001). Conclusion RDW width can be useful for prediction of in-hospital mortality in patients with seizures admitted to the ICU, and it provides additional prognostic value beyond the APACHE IV score alone.