Red cell distribution width is a prognostic factor in severe sepsis and septic shock.

Objective: This study was performed to investigate the association of red cell distribution width (RDW) with 28-day mortality in patients with severe sepsis and septic shock.

Methods: We performed a retrospective analysis of patients with severe sepsis and septic shock. Patients' demographic data, comorbidities, the blood test results including RDW at admission to the emergency department, and Acute Physiologic and Chronic Health Evaluation II score were compared between 28-day survivors and nonsurvivors. Red cell distribution width was categorized into tertiles as 14% or less, 14.1% to 15.7%, and 15.8% or greater. Multivariate Cox proportional hazards regression analysis was performed to determine the risk factors for mortality.

Results: A total of 566 patients were included, and overall mortality was 29%. Red cell distribution width was significantly higher in nonsurvivors than in survivors, and the corresponding mortality of patients with an RDW of 14% or less, 14.1% to 15.7%, and 15.8% or greater was 13.1%, 30.1%, and 44.9%, respectively (P < .001). In Cox proportional hazards analysis, groups with higher RDW are independently associated with 28-day mortality compared with groups with an RDW of 14.0% or less: RDW 14.1% to 15.7% (hazard ratio, 1.66; 95% confidence interval [CI], 1.00-2.76) and RDW of 15.8% or greater (hazard ratio, 2.57; 95% CI, 1.53-4.34). The area under the receiver operating curve of RDW was 0.68 (95% CI, 0.63-0.72).

Conclusion: Red cell distribution width is associated with 28-day mortality in patients with severe sepsis and septic shock.