Background: Combination therapy with inhaled corticosteroids (ICSs) and long-acting beta(2)-agonists (LABAs), or treatment with high doses of ICSs alone improves asthma control when therapy with low-dose ICSs is not sufficient. However, it is not known which of these treatment options is more effective in sustaining asthma control.
Objectives: To evaluate the effect of increasing the ICS dosage vs adding LABAs on the time spent with well-controlled asthma or poorly controlled asthma.
Methods: Post hoc analysis of the Formoterol and Corticosteroid Establishing Therapy study, which compared a fourfold increase in the budesonide dose with and without formoterol.
Results: Time with well-controlled asthma was improved by 19% (95% confidence interval [CI], 3 to 35%; p = 0.017) by adding formoterol, 24 microg/d, to therapy with budesonide, 200 microg/d, compared to 2% (95% CI, -9 to 12%; p = 0.76) with therapy with budesonide, 800 microg/d, alone. Time with well-controlled asthma was further improved by 29% (95% CI, 13 to 47%; p < 0.001) by adding formoterol to therapy with budesonide, 800 microg/d. Time with poorly controlled asthma was significantly reduced using the same interventions by 43% (95% CI, 25 to 57%), 22% (95% CI, 7 to 44%), and 50% (95% CI, 30 to 64%), respectively. Adding formoterol to budesonide was significantly more effective in increasing time with well-controlled asthma when compared to increasing the budesonide dose fourfold (increase, 16%; 95% CI, 1 to 33%; p = 0.035), with a trend for a greater reduction in time with poor control (decrease, 21%; 95% CI, -5 to 42%).
Conclusion: The addition of formoterol to therapy with low-dose budesonide increases the probability of well-controlled asthma compared to a substantial increase in the dose of an ICS.