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.

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.

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.

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.