title: Does the addition of RDW improve current ICU scoring systems?
abstract: BACKGROUND
  The aim of this study was to evaluate whether the addition of red blood cell distribution width (RDW) improves the prognostic value of current intensive care unit (ICU) scoring systems, namely APACHE III.
  
  
  METHODS
  All patients admitted to a mixed ICU in Brisbane between June 2013 and July 2014 for whom RDW was available were included in the study. Analyses included descriptive statistics, linear regression correlation, and receiver operating characteristic (ROC) curves.
  
  
  RESULTS
  The study included 708 patients for whom both ICU mortality prediction and RDW were available. In univariate analysis higher RDW values were associated with increased hospital mortality. Adding RDW to APACHE III increased the area under the ROC marginally (from 0.9586 to 0.9613). RDW was not correlated with C-reactive protein, white cell count, or patient's length of stay in ICU.
  
  
  CONCLUSIONS
  RDW was an independent predictor of mortality. The addition of RDW to APACHE III improved its mortality prediction marginally. The underlying mechanism of RDW elevation warrants further investigation.
authors: Faculty of Health Sciences and Medicine, Bond University, Robina, Australia.
authors: Sarah
authors: S
authors: Loveday
authors: Wesley Laboratory, Sullivan Nicolaides Pathology, Taringa, Australia.
authors: Leanne
authors: L
authors: Sinclair
authors: Faculty of Health Sciences and Medicine, Bond University, Robina, Australia; RCPAQAP, Sydney, Australia. Electronic address: tony.badrick@rcpaqap.com.au.
authors: Tony
authors: T
authors: Badrick
mesh_terms: D018806:APACHE; D000368:Aged; D004909:Erythrocyte Indices; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D012372:ROC Curve
keywords: APACHE; ICU scoring systems; RDW