Previous studies have demonstrated up-regulation of FKBP51 gene expression following treatment with steroids, making it a potential biomarker of steroid exposure. It is therefore also a potential biomarker of non-adherence to inhaled corticosteroid therapy. The investigators plan to assess the feasibility of distinguishing non-adherent subjects who are by omission steroid naïve from adherent subjects, steroid exposed subjects using FKBP51 gene expression in sputum and throat swabs.