The Italian Registry of Patients With Chronic Obstructive Pulmonary Disease

The temporal relationship of observation period to time of participant enrollment will be both retrospective and prospective. A digital dataset will be shared with the participating centers. The following variables, if available, will be collected. Demographic and clinical variables: * Age, sex, height, weight, BMI, waist circumference. * Pneumonia episodes in the last 12 months and number of hospitalizations for pneumonia. * Number of pulmonary rehabilitation cycles performed * Vaccination status (Flu, SARS-CoV-2, pneumococcus, human respiratory syncytial virus, herpes zoster) COPD characteristics: * Date of COPD diagnosis. * COPD exacerbations in the year before the index date (mild, moderate, severe exacerbations), hospitalizations and/or access to ICU. * Type, dosages and duration of antibiotic and systemic corticosteroid treatments during exacerbations. * Respiratory symptoms evaluated with mMRC and CAT * Frequency and purulence of sputum, cough frequency * Inhaled bronchodilator/corticosteroid therapy and type of device used, any treatment changes at index date or during follow up. * Mucolytic agents (active molecules and dosage) * Chronic use of azithromycin * Therapy with roflumilast. * Biological therapies (type of active molecules, duration, switch). * Long-term oxygen therapy (FiO2, average flow), presence of tracheostomy and any invasive or non-invasive ventilatory support Comorbidities: * Concomitant respiratory diseases, history of exposure to risk factors, smoking history (active, former and non-smoker). * Cardiovascular comorbidities and complications in the last 12 months before index date and during follow up * Cardioactive pharmacological therapies * Charlson score * Other comorbidities Biological and functional variables: * Blood tests (RBC, Hb, hematocrit, MCV, PLT, WBC differential, CRP, glycemia, creatinine, uremia, NT-proBNP, cholesterol). * Cardiopulmonary exercise test. The variables collected will include: VO2max, WR max, HRmax, VE max, VEmax, VE/VO2 ratio, PET CO2, O2 pulse, anaerobic threshold, A-a gradient. All values will be collected as absolute and as percentage of predicted values. * Nocturnal oximetry: FiO2, T-90, mean SpO2, ODI. * Polysomnography: type of support (e.g. CPAP or NIMV), FiO2, apnea-hypopnea index (AHI; obstructive, central, and mixed type), AI, oxygen desaturation index (ODI), T-90, Cheyne-Stokes respiration, snoring and body position during the exam. * 6 minutes walking test: FiO2, distance walked in meters and predicted value, SpO2 at the beginning and end of the test, desaturation, if SpO2\<90, modified Borg dyspnea score at the beginning and end of the test. * Gas exchange: SpO2, FiO2, Blood Gas Analysis (pH, PaO2, PaCO2, HCO3-, A-a gradient, FiO2, PaO2/FiO2) * Lung function test pre- and post-bronchodilator: FVC, FEV1, FEV1/FVC, FEF 25-75, VC, IC, FEV1/VC. All values will be collected as absolute values, ratio and percentage of predicted values. * Body plethysmography pre- and post-bronchodilator: TGV, RV, TLC, RV/TLC, IC/TLC, sRAW. All values will be collected as absolute values, ratio and percentage of predicted values * Diffusion capacity of the lung for carbon monoxide: DLCO, KCO, VA, TLC/VA * Fractional exhaled nitric oxide * Chest imaging: radiography or CT scan, presence of emphysema (panlobular or centrolobular), bronchiectasis or interstitial lung disease. * Ecocardiography: ejection fraction, pathological signs, PAPs, left ventricular hypertrophy and left atrial, right ventricular or left ventricular enlargement. * Coronary angiography: if pathological for stenosis and number of involved vessels, PTCA or CABG. All these items will be also valued during the follow up period, with an emphasis on COPD exacerbations and date and cause of death.