In the Women's Health Initiative study there was a relative risk 1.41 at 5.2 years of the development of a stroke (comparing oestrogen plus progestogen arm vs. placebo group) (1) - this meant an increased absolute risk of 8 per 10,000 women per year.
NICE state with respect risk of stroke with HRT (2):
Explain to women that taking oral (but not transdermal) oestrogen is associated with a small increase in the risk of stroke
|Current HRT users||Treatment duration <5 years||Treatment duration 5-10 years||>5 years since stopping treatment|
|Women on oestrogen alone||RCT estimate||0 (-5 to 10)||No available data||No available data||1 more (-4 to 9)|
|Women on oestrogen alone||Observational estimate||3 more (-1 to 8)||No available data||No available data||No available data|
|Women on oestrogen + progestogen||RCT estimate||6 more (-2 to 21)||No available data||No available data||4 more (-1 to 13)|
|Women on oestrogen + progestogen||Observational estimate||4 more (1 to 7)||No available data||No available data||No available data|
Writing Group for the Women's Health Initiative Investigators. Risks and benefits of estrogen plus progestin in healthy postmenopausal women. Principal results for the Women's Health Initiative Randomized controlled trial. JAMA 2002; 288:321-333.
Last reviewed 01/2018