Compared with baseline , the mean VMS frequency at week 8 decreased to 3.9 ( 95 % CI , 2.9-4 .9 ) VMS per day ( 52.9 % reduction ) in the estradiol group , to 4.4 ( 95 % CI , 3.5-5 .3 ) VMS per day ( 47.6 % reduction ) in the venlafaxine group , and to 5.5 ( 95 % CI , 4.7-6 .3 ) VMS per day ( 28.6 % reduction ) in the placebo group .