Wake after sleep onset ( WASO ) was improved on nights 1/2 and 27/28 ( ratio , vestipitant versus placebo [ 95 % confidence interval ] : 0.76 [ 0.65 , 0.90 ] , P = 0.001 and 0.79 [ 0.65 , 0.96 ] , P = 0.02 , respectively ) , demonstrating maintenance of the effect following repeated dosing .