Prior to the very large Women's Health Initiative (WHI) study, first reported in 2002, most studies of hormone therapy (HT) in postmenopausal women showed that it had a positive effect on heart disease. The WHI study was designed to be a placebo-controlled, prospective, randomized trial that would definitively establish the value of HT in the treatment of post-menopausal women. The conclusions of the WHI study, much to almost everyone's surprise, showed small but very real increases in both cardiovascular disease and breast cancer among the women in the HT treatment groups.
As a result of these reports, many physicians began to counsel their patients to stop their HT regimens since, though the hormones relieved menopausal symptoms, HT was placing them at increased risk for heart disease and breast cancer. This situation left many women in a difficult quandary: quit HT and live with the often very uncomfortable symptoms of menopause, or stay on HT and increase the risk of developing a serious medical condition.
Once the initial furor over the report's conclusions died down, professionals began to take serious, discerning looks at the design of the WHI study. Some very interesting problems with the design of the study and its conclusions were discovered. Many knowledgeable investigators now believe that the WHI study was seriously flawed and cannot be used to generalize about the best course of action for many postmenopausal women.
Key among the problems of the WHI are that (1) the women in the study, with an average age of 63, were disproportionately older than the general population; (2) these women had never been on any type of hormone regimen post-menopause; and (3) the particular HT regimen chosen could easily explain the negative results, particularly since, before the WHI, this form of HT had never been demonstrated to prevent cardiovascular disease.
These facts do not change the findings of the WHI study, but they render the findings much less relevant for most postmenopausal women.