BACKGROUND: The prognostic role of the red blood cell distribution width (RDW) on an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is incompletely understood.OBJECTIVE: To investigate the effect of the RDW on in-hospital and 1-year mortality after an AECOPD.DESIGN: For 442 AECOPD patients, the RDW was measured and clinical characteristics, comorbidities and laboratory measurements were recorded. The RDW that discriminated survivors and non-survivors was determined using a receiver operator characteristic (ROC) curve. The risk factors for in-hospital and 1-year mortality were identified through logistic regression analysis and Cox regression analysis, respectively.RESULTS: Of 442 study patients, 31 died, and 411 survived while in hospital. The area under the ROC curve for RDW for in-hospital death was 0.726 (95%CI 0.631-0.822), with sensitivity of 0.71 and specificity of 0.64 for a cut-off point of 13.75%. An RDW ≥13.75% was a risk factor for in-hospital mortality (relative risk 4.30, 95%CI 1.98-9.58; P < 0.001). Univariate and multivariate Cox regression analysis showed that an RDW ≥13.75% was an independent risk factor for death at 1 year (univariate analysis, hazard ration [HR] 2.33, 95%CI 1.55-3.51; multivariate analysis, HR 1.64, 95%CI 1.08-2.50).CONCLUSION: The RDW was a strong and independent risk factor for in-hospital and 1-year death for AECOPD patients.