Combination therapy with inhaled corticosteroids (ICSs) and long-acting β2-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.
To evaluate the effect of increasing the ICS dosage vs adding LABAs on the time spent with well-controlled asthma or poorly controlled asthma.
Post hoc analysis of the Formoterol and Corticosteroid Establishing Therapy study, which compared a fourfold increase in the budesonide dose with and without formoterol.
Time with well-controlled asthma was improved by 19% (95% confidence interval [CI], 3 to 35%; p = 0.017) by adding formoterol, 24 μg/d, to therapy with budesonide, 200 μg/d, compared to 2% (95% CI, −9 to 12%; p = 0.76) with therapy with budesonide, 800 μg/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 μg/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%).
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.