Both initial red cell distribution width (RDW) and change in RDW during heart failure hospitalization are associated with length of hospital stay and 30-day outcomes

Abstract

Introduction: We examined the predictive ability of red cell distribution width (RDW) and the change in RDW during hospitalization (ΔRDW) for length of stay (LOS) and 30-day outcomes after heart failure (HF) inpatient stay.

Methods: Electronic query of Intermountain Healthcare medical records identified patients (N = 6414) with a primary diagnosis of HF who were discharged between 2004 and 2013, had RDW measured within 24 h after admission, and had RDW tested at least once more during the same hospitalization. ΔRDW was defined as the last RDW within 24 h prior to discharge minus the first RDW.

Results: Median LOS by initial RDW quartiles was Q1: 3.0, Q2: 3.1, Q3: 3.7, and Q4: 4.0 days (P-trend<0.001), and by ΔRDW quartiles was Q1: 4.1, Q2: 3.4, Q3: 3.6, and Q4: 4.7 days (P-trend<0.001). Both initial RDW (16.8 ± 2.8% vs. 16.3 ± 2.7%, P < 0.001) and ΔRDW (0.21 ± 1.09% vs. 0.14 ± 1.04%, P = 0.039) predicted 30-day readmission vs. no readmit. For 30-day decedents vs. survivors, initial RDW was 17.3 ± 3.0% vs. 16.3 ± 2.6% (P < 0.001), while ΔRDW was +0.20 ± 1.14% vs. +0.14 ± 1.04% (P = 0.15).

Conclusions: Greater initial RDW and ΔRDW during HF hospitalization were associated with 30-day mortality, longer LOS, and 30-day all-cause readmission, suggesting both ΔRDW and initial RDW may aid in personalizing prognosis and treatment.

Keywords: 30-day outcomes; Red cell distribution width; heart failure; hospital length of stay; mortality.