The CAT (COPD Assessment Test) questionnaire as a predictor of the evolution of severe COPD exacerbations

Introduction: Since exacerbations of chronic obstructive pulmonary disease (COPD) cause both a great impact on the progression of the disease and generate high health expenditures, there is a need to develop tools to evaluate their prognosis. Method: Multicenter, observational, prospective study that evaluated the prognostic utility of the COPD Assessment Test (CAT) in severe exacerbations of COPD. Anthropometric and clinical variables were analyzed: smoking, history of exacerbations during the previous year, drug treatment, degree of baseline dyspnea, comorbidities; laboratory variables at admission (complete blood count, arterial blood gas and biochemistry) and CAT scores in the first 24 h of admission, on the third day, at discharge and at 3 months. Results: We evaluated 106 patients (91 males) with a mean age of 71.1 (SD 9.8 years), mean FEV1 45.2% (14.7%) and average CAT score at admission of 24.7 points (7.1). At three months after discharge, treatment failure was observed in 39 (36.8%) patients: 14 (13.2%) presented an exacerbation without the need for hospital admission, 22 were readmitted (20.8%) and 3 (2.8%) died during follow-up. The three factors associated with increased risk of failure were a reduction less than 4 units in the CAT at discharge compared to admission, lower hemoglobin levels and treatment with domiciliary oxygen. Conclusions: A change of <= 4 points in the CAT score at discharge compared to that obtained at admission due to a severe exacerbation of COPD, helps to predict therapeutic failure such as a new exacerbation, readmission or death in the subsequent three months. (C) 2015 Elsevier Ltd. All rights reserved.