The Women's Health Initiative (WHI) led to many women needlessly abandoning a treatment that offered symptomatic relief for symptoms of the menopause according to a new study. 

In the aftermath of the 2002 WHI announcement that oestrogen-progestin therapy was being halted prematurely because of safety concerns, the prevalence of prescription hormone therapy (HT) declined immediately and still today is lower than pre-WHI levels.

According to a new study in Menopause, the journal of The North American Menopause Society (NAMS) that analysed more than 17 years of data from the 3,018 participants in the Study of Women's Health Across the Nation (SWAN), HT initiation dropped from 8.6% pre-WHI to 2.8% post-WHI. Similarly, the corresponding decrease in HT continuation was 84.0% to 62.0%.

Such decreases occurred across a wide range of participant subgroups, including younger women and those with more vasomotor symptoms (VMS) for whom HT provided the greatest relief with the least amount of risk. Hormone therapy use recommendations have been modified since 2002 as a result of greater education and the realisation that some of the WHI results were misinterpreted as applying to all women. Today's guidelines allow for greater flexibility to reinforce the benefits of individualised treatment based on the age of the woman and the number of years since menopause.

Although this new study is not the first to document the decline in HT use as a result of the initial WHI findings, it differs by distinguishing between the declines in initiation versus continuation. It also is one of the only known studies to document reasons for discontinuation, concluding that many symptomatic women forego HT because of concerns about study findings that are not truly applicable to them. This specific group includes women aged in their 50s when VMS symptoms, such as hot flashes, are most prevalent, but the risks of HT are lower.

Study results appear in the article "Menopausal hormone therapy trends before versus after 2002: impact of the Women's Health Initiative Study Results."

Dr JoAnn Pinkerton, NAMS executive director, said: "Further analysis of the WHI has shown hormone therapy to be safe and effective for menopausal women who have bothersome hot flashes, night sweats, or sleep disruption if they start hormone therapy while aged younger than 60 or within 10 years of menopause. Unfortunately, fear continues to keep symptomatic women from being offered, or using, hormone therapy."