RESULTS	There was evidence of persistent bronchodilator activity with both active treatments compared with placebo ; this was significant for forced expiratory flow rate between 25 % and 75 % of vital capacity ( FEF25-75 ) -- the mean difference versus salmeterol was 0.39 1/s ( 95 % CI 0.06-0 .70 ) , P = 0.02 , and versus formoterol was 0.35 1/s ( 95 % CI 0.16-0 .53 ) , P = 0.001 .\