Use of unopposed estrogen in women with uteri: prevalence, clinical implications, and economic consequence

Hormone replacement therapy with estrogen/progestin is the treatment of choice for relieving postmenopausal vasomotor symptoms and preventing urogenital atrophy and osteoporosis in women with intact uteri. However, despite the known increased incidence of endometrial hyperplasia when unopposed estrogen is used in such women, this progestin regimen has not been universally adopted.

This study was conducted in a managed care organization to determine the extent of the use of unopposed estrogen in women with intact uteri. Pharmacy claims data for all women 55 years or older with claims for estrogen only from September 1, 1996, to December 31, 1996, were reviewed. A total of 5,209 records were identified, from which 480 were randomly selected. A survey of the members' physicians was then carried out to determine hysterectomy status and was confirmed by chart audit.

Thirty-three (11%) of the members identified had not undergone hysterectomy. Follow-up physician contact revealed that five women did not have a uterus. Use of estrogen without opposing progestin was documented in a substantial percentage of files reviewed. It is of concern that with the documentation of the risks of endometrial hyperplasia and carcinoma in the intact uterus, unopposed therapy still occurs. In addition to the clinical costs, there are economic consequences to this practice. An economic model of unopposed estrogen use was created. A management cost of $1,504 for 3 years was estimated.

Further educational efforts are needed to ensure the use of opposed estrogen in the woman with an intact uterus.