A headline can make a small risk sound enormous, or make an important risk sound trivial. The 2020 postmenopausal-care review illustrates a more useful approach: identify the underlying risk, describe the extra events associated with treatment, and explain which people and formulations were actually studied.
Absolute and relative risk answer different questions
Absolute risk tells you how many people experience an outcome over a stated period. Relative risk compares one group with another. Both can be correct, but they convey different information. A percentage change is difficult to interpret without knowing the starting risk.
For an illustration only—not a hormone-therapy estimate—imagine an event occurring in 2 out of 1,000 people without a treatment and 3 out of 1,000 with it over the same period. The relative increase is 50%, but the absolute increase is 1 additional event per 1,000 people. Neither description should appear without its denominator and time period.
Your starting risk changes the conversation
If two people start with different baseline risks, an identical relative change can produce different absolute changes. That is why family history, prior disease, age and other risk factors matter. In the review’s case-based approach, breast-cancer and cardiovascular assessments are considered before choosing systemic treatment.
A risk calculator does not diagnose cancer or prove that a treatment will cause it. It estimates probability using selected information and has limitations. Ask which model is being used, what it includes and whether the estimate would actually change the plan. The numerical cutoffs discussed in the 2020 paper should not be treated as universal self-prescribing rules.
What the WHI numbers can—and cannot—tell you
The Women’s Health Initiative studied specific oral hormone regimens in a particular population. Santen and colleagues discuss estimates drawn from participants aged 50–59 and express outcomes as events per 1,000 women over five years. They explicitly describe the trends in their figure as not statistically significant.
That qualification matters. A trend is not the same as a firmly established treatment effect. Nor can a result from one estrogen–progestogen combination automatically be applied to every patch, gel, dose or progestogen. The review notes uncertainty in extrapolating these findings to other formulations.
The authors also point out that most WHI participants were not selected because they had bothersome hot flashes. A prevention trial and a symptom-treatment consultation therefore answer overlapping, but not identical, questions.
Turn risk into a shared decision
- What benefit is most likely for the symptom I want to treat?
- What is my estimated starting risk, and what additional risk is associated with this specific treatment?
- How certain is the evidence, and does it apply to someone with my history?
- What alternatives are available, and when will we reassess the decision?
Good counseling does not promise zero risk. It makes uncertainty explicit and considers how much the symptoms affect your life. Treatment choice should reflect both medical eligibility and your preferences.