High red blood cell distribution width is associated with a risk of short-term mortality in hospitalized surgical, but not clinical patients

Abstract

Background & aims: The distribution width of red blood cells (RDW) is a known factor risk for mortality. However, the association between high RDW and short-term mortality in surgical patients is poorly understood. The aim of this study was to evaluate the association of high RDW with all-cause in-hospital mortality, in surgical and non-surgical patients.

Methods: A retrospective study was performed with patients aged 18 years or older, hospitalized in Clinical Medical and Surgery wards, using adjustments based on a conceptual model. Cox regression was used to determine the independent predictors of in-hospital mortality. The RDW cutoff value was 13.6%.

Results: Of the 2923 patients, 46.1% were over 60 years old, 58.7% were male and 4.7% died. The area under the ROC curve was 0.677 (CI 95%: 0.619-0.712). RDW was associated with an adjusted risk for all-cause in-hospital mortality in surgical (HR 1.17 - CI 95%: 1.03-1.32), but not in clinical patients. For every 1% increase in RDW, the risk of all-cause hospital death in surgical patients increased by 17%. RDW ≥13.6% was associated with an adjusted risk of all cause in-hospital mortality in surgical (HR 2.65 - 95%CI: 1.22-5.73), but not in clinical patients.

Conclusions: High RDW was associated with a risk of in-hospital mortality independent of age, sex, hemoglobin level, multimorbidity, nutritional status and immunological condition. We therefore recommend the use of RDW as a possible marker of mortality risk in clinical practice in surgical patients.

Keywords: Hospitalization; In-hospital mortality; Prognosis; Red cell distribution width.