Red Blood Cell Distribution Width/Hemoglobin Ratio Correlate with Severity of Clinical Status in Residents of Long-term Geriatric and Palliative Care

Background: The red blood cell distribution width (RDW) is a simple measure of red blood cell size heterogeneity. A high degree of anisocytosis, expressed by RDW >15%, is observed in certain anemias, but also in other disorders, where RDW >15% is associated with worse prognosis. We questioned whether the RDW/hemoglobin ratio (RDW/Hb) might closer relate to disease severity than RDW. Design: Cross sectional study Patients: 76 residents of two Department of Comprehensive Nursing Care. Method: Physicians classified the patients according to their clinical status in three groups: "stable", “severe-unstable”, and "intermediate". An outside observer extracted from the patients' files the results of RDW (elevated if >15%), hemoglobin, iron, and transferrin. The RDW (%)/Hb (g/dL) ratio and tansferrin saturation (TSAT) were computed. The associations between RDW, RDW/Hb, TSAT, and the patients' clinical status were assessed. Results: In residents of Department A, RDW >15% was found in 33% of 19 stable patients, in 58% of 10 patients with intermediate severity, and in 81% of 10 patients classified severe-unstable. The RDW/Hb ratio >1.4 was found in 24% of stable patients, in 73% with intermediate severity, and in 93% of the severe-unstable patients. In Department B, 36 out of 38 patient's were classified stable: in 61.2 % the RDW was >15% and in 38% the RDW/Hb was >1.4. Conclusions: In a heterogenic population presenting multimorbidity, the RDW and to a higher degree the RDW/Hb (p <0.00001), correlated with the patients' disease severity.