Red blood cell distribution width and the risk of death in middle-aged and older adults

Arch Intern Med. 2009 Mar 9;169(5):515-23. doi: 10.1001/archinternmed.2009.11.


Background: Red blood cell distribution width (RDW), a component of an electronic complete blood count, is a measure of heterogeneity in the size of circulating erythrocytes. In patients with symptomatic cardiovascular disease (CVD), RDW is associated with mortality. However, it has not been demonstrated that RDW is a predictor of mortality independent of nutritional deficiencies or in the general population.

Methods: Red blood cell distribution width was measured in a national sample of 8175 community-dwelling adults 45 years or older who participated in the 1988-1994 National Health and Nutrition Examination Survey; mortality follow-up occurred through December 31, 2000. Deaths from all causes, CVD, cancer, and other causes were examined as a function of RDW.

Results: Higher RDW values were strongly associated with an increased risk of death. Compared with the lowest quintile of RDW, the following were adjusted hazard ratios (HRs) for all-cause mortality (and 95% confidence intervals [CIs]): second quintile, HR, 1.1 (95% CI, 0.9-1.3); third quintile, HR, 1.2 (95% CI, 1.0-1.4); fourth quintile, HR, 1.4 (95% CI, 1.2-1.8); and fifth quintile, HR, 2.1 (95% CI, 1.7-2.6). For every 1% increment in RDW, all-cause mortality risk increased by 22% (HR, 1.22; 95% CI, 1.15-1.30; P < .001). Even when analyses were restricted to nonanemic participants or to those in the reference range of RDW (11%-15%) without iron, folate, or vitamin B(12) deficiency, RDW remained strongly associated with mortality. The prognostic effect of RDW was observed in both middle-aged and older adults for multiple causes of death.

Conclusion: Red blood cell distribution width is a widely available test that is a strong predictor of mortality in the general population of adults 45 years or older.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Intramural

MeSH terms

  • Aged
  • Erythrocyte Indices*
  • Erythrocytes*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Mortality*
  • Risk Factors