The effect of hormone replacement therapy on the survival of UK women: a retrospective cohort study 1984−2017

One of the most persistent misconceptions about HRT is that it increases the risk of negative health outcomes. Many women are hesitant in exploring the available options for managing their menopausal symptoms because of such beliefs. Additionally, many primary care doctors and gynaecologists are similarly reluctant to prescribe HRT because of unfounded fears. Misinterpretation of data from previous cohort studies is likely partly to blame for this reluctance, but there is also an absence of reliable data published in this area, linked to decades of underfunding and neglect.

This study looked at primary care records in the UK from 1984-2017. The study found 105,199 HRT users, which were matched with controls by age and GP Practice (sociodemographic factors). The average age of follow-up was 13.5 years per participant. After pre-existing conditions such as diabetes, cancer and heart disease were excluded, the study found that, compared to controls, women who had taken combined HRT (oestrogen and progestogen) had on average a 9% reduction in all-cause mortality.

There was no significant effect on all-cause mortality for women taking oestrogen-only HRT in any age group. There was also no increased risk of all-cause mortality for women who started the combined HRT at age 46 to 50. The authors conclude that combined HRT was associated with a 9% average reduction in death from all causes, and that oestrogen-only HRT was not associated with any increased risk.

Commenting on the study, Dr Louise Newson said, “This is a very welcome study. In our clinic, which receives referrals from every corner of the UK, sadly we often see women who have been misinformed about the risks of HRT. If prescribed appropriately based on rigorous empirical research, HRT is not only safe but has the potential to prevent bad health outcomes, including several diseases that particularly affect women, such as osteoporosis and dementia. This timely study helps reassure women that evidence-based HRT use is safe, and supports doctors across the UK to provide safe, individualised care.”

“This study supports the emerging consensus that, for most women, the benefits of HRT outweigh the harm.”

Louise Pryor, President of Institute and Faculty of Actuaries, who commissioned the study.