title: Back to the roots of chronic obstructive pulmonary disease: the severity of respiratory impairment matters.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Antonelli-Incalzi
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology* / Q000628:therapy*