Patel, M., Pilcher, J., Hancox, R. J., Sheahan, D., Pritchard, A., Braithwaite, I., …Beasley, R. (2015). The use of β2-agonist therapy before hospital attendance for severe asthma exacerbations: a post-hoc analysis. npj Primary Care Respiratory Medicine, 25, 1-9. https://doi.org/10.1038/npjpcrm.2014.99