Clinical Control Criteria to Determine Disease Control in Patients with Severe COPD: The CLAVE Study

BACKGROUND: Clinical control in chronic obstructive pulmonary disease (COPD) has not been completely characterized. A proposal of clinical control criteria (CCC) has been recently defined and validated as a tool for determining control, but there is scarce information on patients with severe COPD. OBJECTIVE: To evaluate clinical control in severe COPD using the CCC. PATIENTS AND METHODS: The study design was observational, multicenter, cross-sectional study involving 4801 patients with severe COPD in Spain. Clinical control was defined according to clinical impact (dyspnea grade, use of rescue treatment in last week, sputum color, and daily physical activity) and stability (exacerbations in last 3 months and patient’s perception about health status). Clinical control of COPD was alternatively evaluated with the COPD assessment test (CAT) and the presence of exacerbations in the last 3 months. RESULTS: According to CCC, 61.0% of patients had low clinical impact, and 41.4% showed clinical stability. Overall, 29.9% of patients had both low clinical impact and stability (controlled), whereas 70.1% showed high clinical impact and/or no clinical stability (non-controlled). COPD control was also assessed by using only the definition of CAT≤16 and no exacerbations in the last 3 months. Results obtained with this definition were similar to those obtained by CCC, and the concordance between both definitions was high (Kappa index = 0.698). CONCLUSION: By using the CCC, approximately only one third of patients with severe COPD were considered as controlled. Physical activity, adherence to inhalers, age, post-bronchodilator FEV(1), age-adjusted Charlson comorbidity index, and healthcare level were independent factors associated with COPD control.