Usefulness of Initial Red Cell Distribution Width for Predicting Mortality in Severe Trauma Patients Admitted to the Emergency Department

ABSTRACT

PURPOSE: This study investigated the association between the initial red cell distribution width (RDW) and mortality in patients with severe trauma. METHODS: We conducted a retrospective analysis between January and December 2014. Severe adult trauma patients (age≥18, Injury Severity Score≥16), who were treated in our emergency department, were included in this study. We classified patients into four groups in accordance with their RDW (group 1: RDW≤12.3%, group 2: 12.4%≤RDW≤12.6%, group 3: 12.7%≤RDW≤13.2%, group 4: 13.3%≤RDW). They were compared based on the characteristics of their groups. We also compared the baseline characteristics of patients who survived and did not survive. Univariate and multivariate Cox proportional hazard analyses were performed to determine the association between mortality and each variable. RESULTS: We enrolled 364 severe trauma adult patients. The mortality rate was 8.9%, 16.2%, 12.6%, and 20.4% for RDW groups 1, 2, 3, and 4, respectively; there was no statistical significance. The RDW of patients who survived (n=311) and did not survive (n=53) were 12.7% (12.4-13.3%) and 12.9% (12.5-13.6%), respectively, but this was also not statistically significant (p=0.075). Univariate Cox proportional hazard analysis showed a significant difference between the mortality and initial RDW, but a multivariate analysis did not show an independent association between initial RDW and mortality (hazard ratio, 0.729; confidence interval, 0.508-1.047; p=0.087). Moreover, multivariate analysis did not also show a significant difference between RDW quartile groups according to route of hospital visit. CONCLUSION: There was no independent association between the initial RDW and mortality in patients with severe trauma.