Red cell distribution width/albumin ratio is associated with 60-day mortality in patients with acute respiratory distress syndrome

Abstract

Background: Red cell distribution width (RDW) and albumin concentration are associated with clinical outcomes in patients with acute respiratory distress syndrome, but the clinical usefulness of RDW/albumin ratio has not been elucidated. The aim of this study was to evaluate the association between RDW/albumin ratio and 60-day mortality in patients with acute respiratory distress syndrome. Materials and methods: A retrospective review of 228 patients in a medical intensive care unit were performed between January 2014 and April 2018. RDW and albumin were measured at the initiation of invasive mechanical ventilation. The ratio was calculated by dividing the RDW value by the albumin value (%/g/dl). Results: Median patient age was 72 years and 71.1% were males. The severity of illness and organ dysfunction score was significantly higher in non-survivors than in survivors (p < .001), as were the rates of septic shock and acute kidney injury. The median RDW/Albumin ratio was higher in non-survivors than in survivors (5.9 vs. 4.7%/g/dl, p < .001). RDW/albumin ratio was significantly associated with 60-day mortality (hazard ratio 1.134, 95% confidence interval 1.044-1.231, p = .003). The area under the receiver operating characteristic curves for RDW/albumin ratio was higher than that for RDW alone (0.681 vs. 0.576, p = .002). Conclusion: RDW/albumin ratio was associated with 60-day mortality in patients with acute respiratory distress syndrome.