Despite being told that low-dose menopausal hormone therapy is just as effective and less dangerous than high doses, too many American doctors continue giving their female patients high doses, which carry a considerably higher death risk, researchers from Stanford University School of Medicine wrote in the journal Menopause.

During her menopause, a woman’s ovaries produce less estrogen, and she can develop certain symptoms, such as hot flashes, sleep disturbances and irritability, which can be debilitating for some patients. In the USA last year over 6 million women were treated with estrogen and progestin hormones.

A 2002 trial by the Women’s Health Initiative was stopped when a clear link was found between hormone therapy and breast cancer and cardiovascular disease risk. The results of the trial surprised many experts who had thought hormone therapy would have protected against heart disease.

Lead author, Sandra Tsai, MD, MPH , explained that other trials have since demonstrated that lower dose hormone therapies are just as good at treating menopausal symptoms as the “old” higher ones, and with minimal side effects, as well as a much lower risk of developing breast cancer and/or cardiovascular problems.

According to the authors, a significant number of US doctors in 2009 do not appear to be aware of the benefits of switching from high dose to low dose hormone therapy – which even the FDA recommends.

Senior author, Randall Stafford, MD, PhD, said:

    “We’re disappointed. Yes, there was an increase in the use of low-dose preparations, but it was not sizeable.”

The investigators gathered data from physician surveys dated from 2001 through 2009 by the IMS National Disease and Therapeutic Index. The data contain prescribing information from outpatient visits to doctors’ practices.

They did detect some increase in low-dose hormone therapy use, but the increase was much less than they had expected, and “not nearly enough to suggest that physicians were fully incorporating the new evidence into everyday practice.”

We know that approximately two-thirds of patients with menopausal symptoms respond well to low-dose hormone therapy, the authors wrote. However, they found that less than one-third of the patients were on a low dose in 2009.

After the 2002 trial was stopped and published its finding, prescriptions for high-dose hormone therapy for menopausal symptoms fell by 47% by 2004.

Stattford wrote:

    “This is our best example of clinical trial findings dramatically changing practice.”

Even after 2004 the number of hormone therapies continued to fall (much more slowly).

Other studies have also shown that tansdermal delivery – delivering the hormones through the skin – significantly lowers the risk of blood clots and some other health problems. The research team had logically expected more patients would be using a skin patch in 2009 than 2001. This has not occurred.

The authors wrote:

    “We thought that over time there might be greater tailoring of therapy based on characteristics of the individual woman. The bottom line is that over time we didn’t see the level of refinement in clinical practice that we expected.”

They also found that in 2009, as in 2001, most of the patients on hormone therapy were older – the age for greatest risk of dangerous side effects. This surprised the scientists who had expected treatment in 2009 to include many more women either during or just after their menopause.

The authors say they cannot explain definitively why so many doctors are lagging behind well published research. They suggest that perhaps some adjustment by doctors were made after the 2002 trial, and “clinical inertia” subsequently prevailed. Maybe older women, who were happy with their treatment results and not fully aware of the health risk did not want to chance a recurrence of symptoms.

Another reason for a doctor’s reluctance to change could be the speed of results for higher-dose hormone therapy.

Lead author, Sandra Tsai, MD, MPH, wrote:

    “It takes too long to disseminate research into practice. It helps when findings are presented in the media and when physicians discuss findings with their patients.” She suggested that cooperation between research institutions, drug companies and professional societies could help produce consistent clinical guidelines and find the best ways to disseminate the information to both physicians and patients. “There needs to be a lot of collaboration to make this work.”

Stafford said:

    “It takes a huge event to change clinical practice. We haven’t had that big, well-controlled clinical trial hitting the front page of the newspapers, demonstrating that the risks of standard-dose estrogen and progestin therapies are potentially much higher than at lower doses.”

“Trends in menopausal hormone therapy use of US office-based physicians, 2000-2009”
Tsai, Sandra A.; Stefanick, Marcia L.; Stafford, Randall S.
Menopause. doi: 10.1097/gme.0b013e3181f43404

Written by Christian Nordqvist