A study on significance and correlation of red cell distribution width with severity of clinical illness in COVID-19 patients

Abstract

BACKGROUND: Global pandemic COVID-19 is an acute respiratory illness with a high rate of hospitalization and death rate. Red cell distribution width coefficient of variation (RDW-CV), a routine component of complete blood count (CBC) automatically generated by most hematology analyzers is a useful predictor of clinical outcomes in critically ill patients and in those with infection and sepsis. RDW will provide information for early risk stratification of COVID-19 patients, thereby enabling timely intervention for reducing morbidity and mortality. In such a massive pandemic, early stratification of cases based on routinely available biomarkers can be of great help inefficient utilization of critical care and laboratory assets. MATERIALS AND METHODS: We retrospectively studied the significance and correlation of RDW (CV) (admission) with the severity of clinical illness in 800 confirmed cases of COVID-19 between August 2020 and October 2020 at our hospital. Demographic and clinical details were obtained from medical records; data pertaining to CBC were retrieved through electronic records of our fully automated hematology analyzer (NihonKoden 5 part auto analyzer Model-MEK– 7300K). Statistical workup was done and results were analyzed. RESULTS: Of 800 patients, 60% were male. RDW (CV) >14.5 (elevated) seen in 52% males and 47% females. Elevated RDW was noted in 43.6% (300/688) nonsevere illnesses (mild and moderate), 82% (92/112) in the severe illness group. The mean RDW (CV) for mild, moderate, and severe cases was found to be 14.21 ± 0.61, 15.32 ± 0.67, and 16.34 ± 1.64, respectively. The number of survivors was 704 (88%). The number of people who died was 96 (12%). Elevated RDW was seen in 74% (71/96) who died and 45% (321/704) of people who survived. To determine the efficacy of RDW (CV) in identifying the severity of disease, a ROC curve was used in which a cutoff value of 13.65 is obtained with a sensitivity of 97.3% and specificity of 85%. CONCLUSION: Higher RDW (CV) was found to have a significant association with clinical severity and mortality prediction. Hence, it can be considered as one of the important hematological parameters in the workup to efficiently stratify the patients at the earliest in COVID-19.