Evaluation of criteria for clinical control in a prospective, international, multicenter study of patients with COPD

This prospective study aimed to validate the concept of control in COPD, including a sensitivity analysis of the level of control using either clinical criteria or questionnaires (CAT or CCQ). Clinical control was defined as disease stability (ie an absence of exacerbations in the preceding 3 months and stability in CAT or CCQ scores) plus low disease impact (ie low level of symptoms).