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

Summary Introduction We examined the predictive ability of red cell distribution width ( RDW ) and the change in RDW during hospitalization (Δ RDW ) 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. Δ RDW 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 Δ RDW 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 Δ RDW (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 Δ RDW was +0.20 ± 1.14% vs . +0.14 ± 1.04% ( P  = 0.15). Conclusions Greater initial RDW and Δ RDW during HF hospitalization were associated with 30‐day mortality, longer LOS , and 30‐day all‐cause readmission, suggesting both Δ RDW and initial RDW may aid in personalizing prognosis and treatment.