Evidence Summary

What is an Evidence Summary?

Key messages from scientific research that's ready to be acted on

Got It, Hide this
  • Rating:

In postmenopausal women, hormone therapy does not reduce risk of death; it does increase cardiovascular events

Boardman HM, Hartley L, Eisinga A, et al. Hormone therapy for preventing cardiovascular disease in post-menopausal women. Cochrane Database Syst Rev. 2015;3:CD002229.

Review question

In postmenopausal women with or without cardiovascular disease, does hormone therapy reduce the risk of cardiovascular events, such as clots in the veins or lungs, heart attacks, and strokes?


Women are more likely to develop cardiovascular disease after menopause than before menopause. Hormone therapy is often used to control menopausal symptoms. It is thought that hormone therapy might also prevent cardiovascular disease in postmenopausal women.

How the review was done

The researchers did a systematic review based on studies available up to February 2014.

They found 19 randomized controlled trials with 40,410 postmenopausal women (average age 64 years).

Key features of the trials were:

  • women were relatively healthy (9 trials) or had cardiovascular disease (10 trials);
  • hormone therapy included estrogen alone or combined with progestogen;
  • hormone therapy was compared with placebo or no treatment; and
  • health outcomes were measured 7 months to 10 years after treatment or placebo started.

What the researchers found

The quality of evidence was moderate to high.

Postmenopausal women with no previous cardiovascular disease

Compared with placebo, hormone therapy:

  • did not reduce the risk of death overall or death due to cardiovascular causes; and
  • increased risk of stroke, clots in the legs or arms (venous thromboembolism), and clots in the lungs (pulmonary embolism).

Postmenopausal women with previous cardiovascular disease

Compared with placebo, hormone therapy:

  • did not reduce the risk of death overall, death due to cardiovascular causes, or stroke; and
  • increased risk of clots in the arms or legs and clots in the lungs.


In postmenopausal women with or without cardiovascular disease, hormone therapy does not reduce risk of death and increases risk of cardiovascular events.

Hormone therapy vs placebo in postmenopausal women


Number of trials (number of women)

Rate of events with hormone therapy

Rate of events with placebo

Absolute effect of hormone therapy

Women with no previous cardiovascular disease


8 trials (34,422 women)



No effect

Death due to cardiovascular causes

3 trials (28,353 women)



No effect*


4 trials (28,719 women)



About 5 more woman out of 1000 had a stroke

Clots in veins (venous thromboembolism)

6 trials (33,477 women)



About 10 more woman out of 1000 had a venous thromboembolism

Clots in lungs (pulmonary embolism)

3 trials (31,732 women)



About 4 more women out of 1000 had a pulmonary embolism

Women with previous cardiovascular disease


7 trials (5445 women)



No effect*

Death due to cardiovascular causes

6 trials (5259 women)



No effect


5 trials (5172 women)



No effect*

Clots in the veins (venous thromboembolism)

6 trials (4399 women)



About 12 more women out of 1000 had a clot in the veins

Clots in the lungs (pulmonary embolism)

3 trials (3920 women)



About 6 more women out of 1000 had a clot in the lungs

*Although the rates for the 2 groups look a little different, the differences were not statistically significant. This means that the differences could simply be due to chance rather than due to the different treatments.


A harmless, inactive, and simulated treatment.
Randomized controlled trials
Studies where people are assigned to one of the treatments purely by chance.
Systematic review
A comprehensive evaluation of the available research evidence on a particular topic.
The body's network of blood vessels. It includes the arteries, veins, and capillaries that carry blood to and from the heart.

Related Web Resources

  • Healthy Bones: A Decision Aid for Women After Menopause

    This patient decision aid helps women who have gone through menopause and may have osteoporosis decide on methods to keep your bones healthy. It facilitates the process by outlining and comparing the choices such as medicine, menopausal hormone therapy (MHT), and exercise.
  • Breast cancer Screening video

    Canadian Task Force on Preventive Health Care
    Women ages 50-74 should have a mammogram every 2 to 3 years, if they are not at high risk of breast cancer. Discuss with your doctor whether you should have a mammogram if you are over age 75.
  • What are the early signs of ovarian cancer and how do you detect them?

    Symptoms of ovarian cancer can include abdominal bloating or pain, difficulty eating, or more frequent trips to the washroom. Taking oral birth control pills, having breastfed or been pregnant, and some surgical procedures could lower your risk of ovarian cancer.
DISCLAIMER These summaries are provided for informational purposes only. They are not a substitute for advice from your own health care professional. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the McMaster Optimal Aging Portal (info@mcmasteroptimalaging.org).

Register for free access to all Professional content

Want the latest in aging research? Sign up for our email alerts.

Support for the Portal is largely provided by the Labarge Optimal Aging Initiative. AGE-WELL is a contributing partner. Help us to continue to provide direct and easy access to evidence-based information on health and social conditions to help you stay healthy, active and engaged as you grow older. Donate Today.

© 2012 - 2020 McMaster University | 1280 Main Street West | Hamilton, Ontario L8S4L8 | +1 905-525-9140 | Terms Of Use