Study objectives: To evaluate the effectiveness and safety of inhaled salmeterol in patients managed in nonspecialist practice settings.
Design: A randomized, double-blind, 6-month, parallel-group study involving 253 centers.
Setting: Primarily nonspecialist practices (n = 232).
Patients: A total of 911 subjects (417 men; 494 women) who met American Thoracic Society asthma criteria were enrolled and randomized to treatment with either twice-daily salmeterol aerosol (50 microg; n = 455) or matching placebo twice daily (n = 456). Both groups were allowed to take salbutamol as needed. All subjects were previously treated with anti-inflammatory maintenance therapy that was continued throughout the study.
Measurements and results: The primary outcome variable was the proportion of subjects with serious asthma exacerbations defined as an exacerbation requiring hospitalization, emergency department visit, or use of prednisone during the treatment period. A total of 712 subjects competed the study. There was no significant difference in the proportion of subjects experiencing serious exacerbations between the salmeterol and placebo groups (20.8% vs 20.9%, respectively; p = 0.935; power > 88%). Peak expiratory flow was significantly higher in the salmeterol group (398 L/min vs 386 L/min for placebo; p < 0.01). Median daily use of salbutamol was two inhalations for the salmeterol group and three inhalations for placebo (p < 0.001). The proportion of subjects sleeping through the night was significantly higher in the salmeterol group (74%) as compared to placebo (68%; p = 0.028).
Conclusions: Salmeterol treatment is effective in subjects typically cared for in the primary-care setting and does not increase the frequency of severe exacerbations.