A meta-analysis of the clinical significance of red blood cell distribution width in chronic obstructive pulmonary disease

This paper aims to elucidate the association of red blood cell distribution width (RDW) with chronic obstructive pulmonary disease (COPD) and its clinical outcomes. Systematically searched PubMed, Embase, Cochrane Library, and Web of Science for articles up to 11 October 2024, and conducted a comprehensive data integration and meta-analysis. 41 articles with 19,518 participants were included. RDW was higher in COPD versus non-COPD patients (SMD = 0.63, 95% CI = 0.18 ~ 1.08); in AECOPD versus stable COPD (SMD = 0.39, 95% CI = 0.21 ~ 0.57); in COPD with complications (SMD = 0.50, 95% CI = 0.32 ~ 0.68); in deceased versus surviving patients (SMD = 0.63, 95% CI = 0.38 ~ 0.89); and in those with unfavorable outcomes (SMD = 1.21, 95% CI = 0.17 ~ 2.25). Increased RDW was linked to adverse outcomes (OR =1.32, 95% CI = 1.18 ~ 1.48) and predicted mortality (AUC = 0.68, 95% CI = 0.57 ~ 0.80) and other adverse outcomes (AUC = 0.76, 95% CI = 0.67 ~ 0.85) in COPD patients. RDW values differed markedly between COPD and non-COPD patients and among COPD patients of different severities and clinical outcomes, and was an independent predictor of mortality and complication risks.