title: The red cell distribution width as a prognostic indicator in idiopathic pulmonary fibrosis.
abstract: BACKGROUND
  The course of idiopathic pulmonary fibrosis (IPF) is characterized by variable patterns of disease progression. The red cell distribution width (RDW) is a parameter that is routinely reported with all CBC counts. We sought to test the prognostic usefulness of this parameter in a well-defined cohort of patients with IPF.
  
  
  METHODS
  CBCs, demographics, and pulmonary function data from patients with IPF evaluated between January 1997 and June 2011 were collated. Patient outcomes were ascertained from the program's database and the Social Security Death Index.
  
  
  RESULTS
  There were 319 patients with IPF evaluated in whom baseline CBCs were available. The range in the RDW was 11.9 to 21.9 (median 14.1). There were 228 subjects with RDW values ≤ 15 (normal) and 91 patients with RDW values &gt; 15. Patients with normal RDW values had a median survival of 43.1 months compared with 16.3 months for those whose RDW was &gt; 15 (P = .001). There were 198 patients with available serial RDW data. Those patients who had a change in the RDW of less or greater than +0.010/mo had median survivals of 43.0 and 23.9 months, respectively (P = .0246).
  
  
  CONCLUSIONS
  The RDW is a readily available laboratory test result that may provide important, independent prognostic information at baseline and follow-up in patients with IPF. Further studies are warranted to validate this as a biomarker for IPF outcomes, as well as to define the biologic basis for this association.
authors.affiliation: Advanced Lung Disease and Lung Transplant Program, Department of Medicine, Inova Fairfax Hospital, Falls Church, VA. Electronic address: steven.nathan@inova.org.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Nathan
authors.affiliation: Advanced Lung Disease and Lung Transplant Program, Department of Medicine, Inova Fairfax Hospital, Falls Church, VA.
authors.forename: Taylor
authors.initials: T
authors.lastname: Reffett
authors.affiliation: Advanced Lung Disease and Lung Transplant Program, Department of Medicine, Inova Fairfax Hospital, Falls Church, VA.
authors.forename: A Whitney
authors.initials: AW
authors.lastname: Brown
authors.affiliation: Advanced Lung Disease and Lung Transplant Program, Department of Medicine, Inova Fairfax Hospital, Falls Church, VA.
authors.forename: Chelsea P
authors.initials: CP
authors.lastname: Fischer
authors.affiliation: Advanced Lung Disease and Lung Transplant Program, Department of Medicine, Inova Fairfax Hospital, Falls Church, VA.
authors.forename: Oksana A
authors.initials: OA
authors.lastname: Shlobin
authors.affiliation: Advanced Lung Disease and Lung Transplant Program, Department of Medicine, Inova Fairfax Hospital, Falls Church, VA.
authors.forename: Shahzad
authors.initials: S
authors.lastname: Ahmad
authors.affiliation: Advanced Lung Disease and Lung Transplant Program, Department of Medicine, Inova Fairfax Hospital, Falls Church, VA.
authors.forename: Nargues
authors.initials: N
authors.lastname: Weir
authors.affiliation: Inova Research Center, Inova Fairfax Hospital, Falls Church, VA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Sheridan
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D018450:Disease Progression; D004909:Erythrocyte Indices; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000097:blood*; D008297:Male; D011379:Prognosis; D016016:Proportional Hazards Models; D012129:Respiratory Function Tests; D018709:Statistics, Nonparametric; D016019:Survival Analysis
chemical_list: D015415:Biomarkers