Max Rady College of Medicine
Concept: Hormone Replacement Therapy (HRT) Use
Last Updated: 2006-02-16
Definition of HRT
Hormone Replacement Therapy (HRT) is medication containing one or more female hormones, commonly estrogen plus progestin (synthetic progesterone). Some women receive estrogen-only therapy (usually women who have had their uterus removed). HRT is most often used to treat symptoms of menopause such as "hot flashes", vaginal dryness, mood swings, sleep disorders, and decreased sexual desire. This medication may be taken in the form of a pill, a patch, or vaginal cream.
Based on early studies, many physicians believed that HRT might be beneficial for reducing the risk of heart disease and bone fractures caused by osteoporosis (thinning of the bones) in addition to treating menopausal symptoms. However, after the July 2002 release of
"Risks and Benefits of Estrogen plus Progestin in Healthy Postmenopausal Women"
by the Writing Group for the Women's Health Initiative (WHI) (
WHI Web Site: http://www.whi.org
Investigators, the use of Hormone Replacement Therapy (HRT) could be expected to decline. The results of this 5 year study showed healthy postmenopausal women taking estrogen plus progestin versus placebo were at greater risk for Congestive Heart Disease, Breast Cancer, Stroke and Pulmonary Embolism. These results have led physicians to revise their recommendations regarding HRT.
Incidence and Prevalence
of HRT is the proportion of women starting HRT use for the first time (that is, women receiving a prescription for HRT, having not received any HRT drugs in the previous fiscal year).
is the proportion of women using HRT medication.
In Fransoo et al. (2005) the prevalence was defined by the number of Manitoba female residents using HRT drugs in the fiscal year, divided by the number of Manitoba female residents in the province as of Dec. 31 of that year. A woman must have at least one prescription for a HRT drug in the fiscal year to be counted as a prevalent case for that year.
The incidence was defined by the number of Manitoba female residents starting HRT drugs in the fiscal year, divided by the number of Manitoba female residents in the province as of Dec. 31 of that year. A woman cannot have any prescriptions in the year prior to her first prescription of HRT in the study year to be counted as an incident case for that year.
Drug Program Information Network (DPIN) data was used to define this indicator.
HRT drugs included in
Fransoo et al. (2005)
Anatomical Therapeutic Chemical (ATC) Drug Classification System
which was developed by the World Health Organization's
Collaborating Centre for Drug Statistics Methodology: http://www.whocc.no/
. This list was carefully developed and validated by Patricia Caetano for her dissertation research:
Natural and Semi-synthetic Estrogens
Ethinylestradiol (ATC Code G03CA01)
Estradiol (ATC Code G03CA03)
Estrone (ATC Code G03CA07)
- Conjugated estrogens (ATC Code G03CA57)
- Ethinylestradiol (ATC Code G03CA01)
Progestogens and Estrogens, fixed combinations
- Norethisterone and estrogen (ATC Codes G03AA05, G03FA01)
Progestogens and Estrogens, sequential preparations
- Norethisterone and estrogen (ATC Code G03FB05)
Note: This list of drugs should be reviewed by a pharmacist or clinician each time it is used in research, as new formulations are continually being added.
- Anatomical Therapeutic Chemical (ATC) Drug Classification System
- Drug Program Information Network (DPIN) Data
- Hormone Replacement Therapy (HRT)
- Incidence / Incidence Rate
- Fransoo R, Martens P, The Need to Know Team, Burland E, Prior H, Burchill C, Chateau D, Walld R. Sex Differences in Health Status, Health Care Use, and Quality of Care: A Population-Based Analysis for Manitoba's Regional Health Authorities. Winnipeg, MB: Manitoba Centre for Health Policy, 2005. [Report] [Summary] [Additional Materials] (View)
- Rossouw JE, Anderson GL, Prentice RL, LaCroix AZ, Kooperberg C, Stefanick ML, Jackson RD, Beresford SA, Howard BV, Johnson KC, Kotchen JM, Ockene J, Writing Group for the Women's Health Initiative Investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results From the Women's Health Initiative randomized controlled trial. Journal of the American Medical Association 2002;288(3):321-333. [Abstract] (View)
Manitoba Centre for Health Policy
Community Health Sciences, Max Rady College of Medicine,
Rady Faculty of Health Sciences,
Room 408-727 McDermot Ave.
University of Manitoba
Winnipeg, MB R3E 3P5 Canada