Factors Associated With Large Airway Collapse in Severe Asthma Carlos Martinez Rivera; Pere Serra Mitjà; Felipe Andreo García; Astrid Crespo-Lessmann; Alan Jhunior Solis Solis; Alfons Torrego; Ignasi Garcia-Olive; David Ramos-Barbón; Toni Zapata Comas; Vicente Plaza; Jorge Abad; Antoni Rosell;