Objective: To compare the incident rate of abnormal endometrial findings in postmenopausal women receiving treatment with either 60 mg of raloxifene or a continuous combined estrogen plus progestin therapy containing 2 mg of 17 beta-estradiol plus 1 mg of norethisterone acetate for a duration of up to 12 months.
Methods: One thousand eight asymptomatic postmenopausal women with osteoporosis or cardiovascular risk factors with an endometrial thickness of less than 5 mm at baseline participated in this prospective, randomized, double-blind trial that lasted 6 months; 347 of these women also participated in a 6-month extension. Women with repeated bleeding or an increase in endometrial thickness to above 5 mm were subjected to saline-infused sonohysterography or hysteroscopy with biopsy.