ObjectiveTo explore the value of three brief scales (BAP-65 class, DECAF score, and CAPS) on assessing the severity of acute exacerbation in patients with chronic obstructive pulmonary disease(COPD) complicated by hypercapnic respiratory failure. MethodsTwo hundred and forty-four cases with acute exacerbation of COPD complicated by hypercapnic respiratory failure, admitted in West China Hospital from August 2012 to December 2013, were analyzed retrospectively.The scores of each scale were calculated.The areas under the receiver operating characteristic curves (AUROC) of each scale for hospital mortality, mechanical ventilation use, mortality of patients requiring mechanical ventilation, invasive mechanical use were analyzed and compared. ResultsThe AUROCs of BAP-65 class, DECAF score and CAPS for hospital mortality were 0.731, 0.765, and 0.711; for mechanical ventilation were 0.638, 0.702, and 0.617; for mortality of patients requiring mechanical ventilation were 0.672, 0.707, and 0.677; for invasive mechanical ventilation use were 0.745, 0.732, and 0.627(BAP-65 vs.CAPS, P < 0.05).Mortality and mechanical ventilation use increased as the three scales escalated.In the patients whose BAP-65 or DECAF score were more than 4 points, the hospital mortality was nearly 50%, and about 95% of the patients underwent mechanical ventilation. ConclusionsThe BAP-65 class, DECAF score, and CAPS of patients on admission have predictive values on assessing the severity of acute exacerbation in patients with COPD complicated by hypercapnic respiratory failure, especially the simple and practical BAP-65 class and DECAF score.