Hip fracture patients who experience a greater fluctuation in RDW during hospital course are at heightened risk for all-cause mortality: a prospective study with 2-year follow-up

Abstract

This study aims to detect whether there remains valuable prognostic information in fluctuation of red cell distribution width (RDW) in hip fracture patients. Results show that this readily available parameter may provide a more effective strategy for assessment of mortality risk, therefore providing a reference for clinical planning and decision-making.

Introduction: Prognostic values have been found in the fluctuation of some hematologic parameters. The red cell distribution width (RDW) routinely reported with all complete blood cell counts (CBC) has proven to be associated with poor outcomes in various diseases. However, whether the fluctuation in RDW is predictive of long-term mortality in hip fracture patients treated with surgery remains unknown.

Methods: One thousand three hundred thirty hip fracture patients who underwent surgery from January 1, 2000 to November 18, 2012 were recruited in this prospective cohort study. Fluctuation in the RDW between admission and discharge was measured, and a Kaplan-Meier (KM) analysis and multivariable Cox regression model were applied to evaluate the relationship between this fluctuation and mortality. Risk factors for a larger fluctuation were detected by using Logistic regression analyses.

Results: In addition to the admission RDW, a high RDW level at the time of discharge was also associated with an increased risk of death, while no significant difference was found in the postoperative RDW. Fluctuation in the RDW between admission and discharge was an independent risk predictor for 2-year mortality (HR 1.45 95%CI 1.06-2.00, p = 0.022). Factors affecting the change in the RDW between admission and discharge included both the demographic characteristics of the patients and clinical interventions.

Conclusion: Hip fracture patients who experience a greater fluctuation in RDW during the hospital course are at a heightened risk for 2-year all-cause mortality.

Keywords: All-cause mortality; Fluctuation in RDW; Hip fracture; Risk factor.