ASTUTE is a longitudinal, randomised, multicentre, and multinational pragmatic study of patients with Chronic Obstructive Pulmonary Disease to evaluate the comparative effectiveness of Aclidinium bromide/formoterol fumarate fixed-dose combination (Duaklir™ Genuair®) and Standard of Care bronchodilators in patients treated with long acting bronchodilator monotherapies OR patients who abide to the following treatment category: patient is newly diagnosed, or naïve to maintenance therapy, or treated with short-acting bronchodilators as rescue medication, or has not been treated with long-acting bronchodilators in the last 3 months.