Red cell distribution width is an independent predictor of mortality in hip fracture

Abstract

Background: the red cell distribution width (RDW), an automated measure of variability in the red blood cell size on full blood count (FBC) is an independent predictor of mortality in several disease states and in healthy older people. Objective: we wanted to determine the prognostic value of RDW in patients following a hip fracture-a condition associated with high mortality. Design: we examined the relationship between admission RDW and mortality in 698 consecutive patients admitted with hip fracture. Method: regression analysis was used to examine admission RDW and subsequent mortality, adjusting for admission haemoglobin, mean corpuscular volume, age, gender, pre-morbid residence and independence level, Charlson co-morbidity index and post-operative complications. Results: the mean age was 78 ± 13 years. Unadjusted 1-year mortality was 12, 15, 29 and 36% across quartiles of increasing RDW. Along with age and post-operative complications, RDW remained significantly associated with in-hospital, 120-day and 1-year mortality [adjusted hazard ratios: HR: 1.119, 95% CI: (1.000-1.253), P = 0.05, 1.134 (1.047-1.227), P = 0.004 and 1.131 (1.067-1.199), P < 0.001, respectively]. These relationships remained significant at all three time points on repeat analysis in non-anaemic patients (n = 548). Conclusion: RDW, a widely available parameter on FBC, is independently associated with an increased risk of short- and long-term mortality following hip fracture. © The Author 2012. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved.