or the β-agonist salmeterol (Serevent) in a multicenter, double-blind, international study. All enrollees had moderate-to-severe COPD (post-bronchodilator forced expiratory volume in 1 second ...

Study objective: To compare the safety of salmeterol xinafoate or placebo added to usual asthma care. Design: A 28-week, randomized, double-blind, placebo-controlled, observational study.