The evidence base for HRT: what can we believe?

AbstractPrior to the unexpected early termination of the Women’s Health Initiative (WHI) trial of continuous conjugated equine estrogens (CEE) and medroxyprogesterone acetate (MPA), the prevailing view was that hormone replacement therapy (HRT) was a low-risk intervention with immediate value for symptom relief in recently menopausal women, and that it probably conferred long-term protection against the major chronic diseases that affect women after menopause. Rather than replicating prior studies, the WHI was designed to test whether the beneficial associations consistently seen in women starting HRT near menopause would be found in women well beyond menopause. Views of the benefits and risks of HRT changed dramatically in 2002 with the unexpected early termination of the CEE + MPA trial and the alarming initial WHI report. HRT use plummeted world-wide, driven by fear of breast cancer and skepticism about cardiovascular benefits. Stunningly, the contrasting findings of the WHI trial of CEE alone reported...