Anxiety and COPD Evaluation

This prospective, multicenter, cohort study is designed to validate Anxiety Inventory Respiratory Disease questionnaire in patients with Chronic Obstructive Pulmonary Disease (COPD). The primary purpose of this study is to assess the validity of the Anxiety Inventory Respiratory (AIR) scale in detecting anxiety in relation to the DSM-V criteria in patients with COPD. * To evaluate associations between COPD symptom scores assessed by the CAT questionnaire and MMRC dyspnea scale and measures of depression and anxiety * To evaluate associations between physiologic measures of lung function (spirometry) and exercise tolerance (6 minute walk) and measures of depression and anxiety * To evaluate associations between exacerbations of COPD and the prevalence of anxiety and depression in a cohort of COPD patients