Red cell distribution width: A new parameter for predicting the risk of exacerbation in COPD patients.

BACKGROUND Red cell distribution width (RDW) is a numerical measurement of the size variability of erythrocytes and is routinely reported as a component of complete blood count in the differential diagnosis of anemia. In recent years, researchers have reported high mortality and poor prognosis associated with higher RDW in populations with cardiovascular disease, cancer, pneumonia, and chronic obstructive pulmonary disease (COPD). The aim of the study is to evaluate the role of RDW in predicting the risk of COPD exacerbations and the impact of symptoms. METHODS We designed an observational retrospective study based on patients hospitalized for acute exacerbation of COPD, between January 2015 and December 2018. RESULTS We included 169 patients, 120 at GOLD four stage. RDW was significantly higher in COPD patients vs controls (P = .014). We found a positive correlation with c-reactive protein (r  = 0.375, P < .01), COPD assessment test (CAT) Score (R2 = 0.658, sy.x = 2.226; P < .01), number of exacerbations (R2=0.289; sy.x = 0.86; P = .002), and GOLD score (r = 0.30; P = .05). In ROC curve analysis, the area under the curve of RDW for the identification of frequent exacerbator was 1.0 (95% confidence interval, 1.0-1.0; P < .0001). CONCLUSION Our data show that elevated RDW may be a useful tool in predicting the risk of exacerbation in COPD patients and may be a good indicator of the impact of symptoms.