Results from the Estonian postmenopausal hormone therapy trial [ISRCTN35338757]

At present the Women's Health Initiative trial is the only reported randomised controlled trial studying the effects of hormone therapy among healthy postmenopausal women. The Women's Health Initiative reports have been criticized for lacking in generalisability, due to the characteristics of the trial population. We aimed to compare the health effects of oral continuous combined hormone therapy with a placebo and non-treatment among healthy Estonian women.

Eligible women were randomised into a blind group of hormone therapy versus placebo and into a non-blind group of open label hormone therapy versus non-treatment. One thousand seven hundred and seventy-eight postmenopausal women aged 50-64 at the time of sampling were recruited in 1999-2001 at three clinical centers in Estonia. Participants received conjugated equine oestrogens, 0.625 mg/d, plus medroxyprogesterone acetate, 2.5mg/d, or conjugated equine oestrogens, 0.625 mg/d, plus medroxyprogesterone acetate, 5mg/d, if less than 3 years had passed since menopause at recruitment, or matched placebo or non-treatment. Trial treatment was stopped gradually from 1 January 2004 to 31 May 2004.

After a follow-up period from 2.0 to 5.0 years the combined hazard ratio, stratified by blinding and adjusted for age at recruitment and former oral contraceptive use was 1.12 (95% confidence interval [CI]: 0.90-1.40) for coronary heart disease, 1.24 (95% CI: 0.85-1.82) for cerebrovascular disease, 1.36 (95% CI: 0.73-2.52) for total cancer, and 0.61 (95% CI: 0.42 to 0.89) for bone fractures.

The results from the Estonian Postmenopausal Hormone Therapy randomised trial are consistent with the Women's Health Initiative findings.