Published: 30 September 2002

Hormone Replacement Therapy - Letter to Healthcare Professionals

Information on this subject has been updated. Read the most recent information.

This letter will be posted to all doctors and pharmacies on Wednesday 2 October. 

Medsafe letterhead

30 September 2002





Dear Health Professional

In July 2002, the Women's Health Initiative Study1 published results, summarised below, demonstrating that the risks of routine combined oestrogen and progestogen hormone replacement therapy (HRT) outweighed the benefits.

Table 1. Summary of incidence of adverse events based on results from the WHI study. Data derived from women aged 50 to 79 years, after an average follow-up of 5.2 years.

Adverse Event Relative Risk
HRT vs placebo at 5.2 years
(95% CI)
Change in number of
adverse events per 10,000
women in one year
Breast cancer 1.26 (1.00-1.59) 8 extra
Heart disease 1.29 (1.02-1.63) 7 extra
Stroke 1.41 (1.07-1.85) 8 extra
Pulmonary embolism 2.13 (1.39-3.25) 8 extra
Colorectal cancer 0.63 (0.43-0.92) 6 fewer
Hip fracture 0.66 (0.45-0.98) 5 fewer

Following publication of the WHI study, the New Zealand Guidelines Group and the Medicines Adverse Reactions Committee (MARC) conducted independent reviews of the literature on the risks and benefits of combined HRT. The Guidelines Group key messages are enclosed (see link below) and are supported by the MARC.

On completion of its review the MARC concluded that:

The MARC advice to limit the duration of HRT use raises questions about the role of HRT in the management of osteoporosis. The Committee will convene an expert advisory panel to advise Medsafe on this issue. The outcome will be made available to PHARMAC for their review of HRT medicines. Further advice and information will be published in Prescriber Update.

Yours sincerely

Stewart S Jessamine
Principal Technical Specialist


  1. Writing Group for the Women's Health Initiative (WHI) Investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: Principal results from the WHI randomized controlled trial. JAMA 2002;288:321-333.

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Link to New Zealand Guidelines Group - Hormone Replacement Therapy Update - Key Messages (September 2002)
(This is a 325KB PDF file which requires Adobe Acrobat Reader to enable viewing - download Adobe Acrobat Reader)