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Oral and Transdermal Estrogen Therapy Evaluated

Menopause; ePub 2017 Jul 10; Crandall, et al

Clinical outcomes were similar for oral conjugated equine estrogen (CEE) compared to oral or transdermal oral estradiol (E2) containing regimens, a recent study found. The study used data from 45,112 participants of the Women’s Health Initiative Observational Study and examined associations of estrogen type and oral CEE dose with time to first global index event (GIE), defined as coronary heart disease, breast cancer, stroke, pulmonary embolism, hip fracture, colorectal cancer, endometrial cancer, or death. Average follow-up period was 5.5 years. Researchers found:

  • Oral CEE <0.625 md/d + progestogen (P) users had a lower risk of GIE (adjusted hazard ratio [aHR] 0.74) vs oral CEE 0.625 mg/d + P users.
  • GIE risk in oral CEE 0.625 mg/d + P users was greater with at least 5-year use (aHR, 1.22) than with <5-year use.
  • Among women with prior hysterectomy compared with women taking oral CEE 0.625 mg/d for <5 years, GIE risk was similar with oral CEE below 0.625 mg/d, E2, and transdermal E2, whether used for <5 years or for at least 5 years.


Crandall CJ, Hovey KM, Andrews C, et al. Comparison of clinical outcomes among users or oral and transdermal estrogen therapy in the Women’s Health Initiative Observational Study. [Published online ahead of print July 10, 2017]. Menopause. doi:10.1097/GME.0000000000000899.