Previous analyses of the Women's Health Initiative trials-which were designed to assess the benefits and risks of hormone therapy in postmenopausal women-did not assess all-cause or cause-specific mortality or the potential effect on mortality of age. However, this was the focus of researchers in this 18-year follow-up of the Women's Health Initiative trials, which included 27,347 women 50 to 79 years old who were enrolled from 1993 to 1998 at 40 U.S. medical centers. Participants included 16,608 women with a uterus who were randomized to receive daily oral estrogen (conjugated equine estrogens) plus progesterone (medroxyprogesterone acetate) or placebo and 10,739 women who had had a hysterectomy and were randomized to receive estrogen alone or placebo.

The researchers found that taking estrogen plus progesterone for a median of 5.6 years, or estrogen for a median of 7.2 years, did not increase the risk of death (all cause, cardiovascular, or cancer). All-cause mortality rates were essentially the same: 27.1% among women receiving hormone therapy and 27.6% among those receiving placebo, with no differences across age groups. One limitation of the study is that the researchers only assessed one formulation, dose, and route of administration, so it's unknown if these rates would be similar in women receiving different hormone preparations.

The researchers cautioned that although these results continue to support guidelines that endorse the use of hormone therapy to manage moderate to severe postmenopausal symptoms, it remains unclear if the benefits outweigh the risks of longer-term treatment. They write: "In clinical decision making, these considerations must be weighed against the evidence linking untreated vasomotor symptoms in midlife women to impaired health and quality of life, disrupted sleep, reduced work productivity, and increased health care expenditures."

REFERENCE