The objectives of this research seminar are to redefine severe exacerbations of COPD, review upcoming biomarkers and identify key interventional needs. This seminar aims to highlight severe exacerbations as distinct events, with important differences to mild and moderate exacerbations. The research seminar will allow inclusion and understanding of CICERO, an ERS Clinical Research Collaboration, and provide opportunity for participants to become part of the CATALINA study, an upcoming pan-European observational study.