The Single combination budesonide-formoterol inhaler Maintenance And Reliever Therapy (SMART) regimen reduces severe asthma exacerbations in patients, but whether the high doses of corticosteroid and β agonist increase the risk of adverse effects with both short-term and cumulative exposure is not certain. Our aim was to investigate whether the SMART regimen would reduce the risk of overuse of β agonist, reduce the likelihood of patients to seek medical review when such episodes occurred, and if any reduction in severe asthma exacerbations would be at the cost of a higher burden of systemic corticosteroid.