Red blood cell distribution width predicts long-term outcomes in sepsis patients admitted to the intensive care unit

Although some underpowered studies have proven that increased red blood cell distribution width (RDW) may be associated with short-term prognosis of sepsis, the long-term prognostic value of RDW remains largely unknown.

This retrospective observational study was based on the Medical Information Mart for Intensive Care III (MIMIC III), a large critical care database. Baseline RDW and conventional disease severity scores were extracted along with data on 4-year mortality, of adult patients with severe sepsis upon first admission to the intensive care unit (ICU). The prognostic value of RDW was analyzed with Kapan-Meier cure, Cox model, receiver operating characteristic (ROC) curve analysis, net reclassification index (NRI) and integrated discriminatory index (IDI).

A total of 4264 subjects were included. The area under ROC curve of RDW for predicting 4-year mortality was 0.64 (95% CI: 0.63-0.66). In multivariable Cox model, increased RDW was independently associated with all-cause mortality, irrespective of anemia. With conventional severity scores as reference, RDW had continuous NRI comprised between 0.18 and 0.20, and IDI comprised between 0.30 and 0.40.

RDW values significantly predicts long-term all-cause mortality in critically ill patients with severe sepsis beyond conventional severity scores.