Long-term compliance with estrogen replacement therapy in surgical postmenopausal women: Benefits to bone and analysis of factors associated with discontinuation

Objective: To evaluate prospectively the effects of long-term estrogen replacement therapy (ERT) on bone density in surgical postmenopausal women treated for 5 years with two different modalities and to determine the factors associated with discontinuation of ERT. Design: We included in the present study 165 women (mean age, 46.8 +/- 3.6 years) who had undergone surgical menopause. ERT was prescribed immediately after surgery, and bone mineral density was measured at the lumbar spine before the women entered the study and at 12, 24, 36, 48, and 60 months after being included. Treated patients were assigned at random to one of two groups, The first group received conjugated equine estrogens 0.625 mg/day continuously, and the second group received transdermal 17 beta-estradiol 50 mg/day continuously. Treated groups were compared with a nontreated control group. Results: Our data showed that although ERT clearly protected against bone loss in women who had experienced surgical menopause, only one third of the treated patients continued ERT at the end of follow-up. The main reason for discontinuation was fear of cancer (36.1% of cases). In addition, no differences were observed between oral and transdermal groups of treatment. Conclusions: Long-term ERT may have a protective effect against bone loss in surgically postmenopausal women; however, two thirds of treated patients discontinued therapy after 5 years and 43% of them presented a negative balance on bone mass in one or more bone density assessments. For this reason, enhancing compliance and monitoring treatment are mandatory. (Menopause 1999;6:307-311. (C) 1999, The North American Menopause Society.).