The WHI ten year's later: an epidemiologist's view

Area of Science:

• Reproductive Health
• Epidemiology
• Clinical Trials

Background:

• Menopausal hormone therapy (MHT) was previously thought to have benefits outweighing risks.
• The Women's Health Initiative (WHI) trials provided definitive, yet surprising, results regarding MHT safety.
• Post-trial analyses have attempted to reconcile WHI findings with prior expectations and observational data.

Purpose of the Study:

• To review lessons learned from the WHI clinical trials for future epidemiological research.
• To discuss the implications of WHI findings for understanding menopausal hormone therapy (MHT).
• To advocate for integrating observational and intervention study designs in public health research.

Main Methods:

• Review of Women's Health Initiative (WHI) clinical trial data and outcomes.
• Analysis of subsequent epidemiological studies and critiques of WHI results.
• Discussion of methodological approaches in observational and intervention research.

Main Results:

• Oral conjugated equine estrogens (CEE) alone or with medroxyprogesterone acetate (CEE+MPA) should not be used for primary prevention of chronic diseases in postmenopausal women.
• The risks associated with CEE and CEE+MPA outweigh the benefits for primary prevention.
• Conflicting results between observational studies and clinical trials may stem from similar underlying data, necessitating creative analysis.

Conclusions:

• The WHI trials offer critical lessons for epidemiological study design and interpretation.
• Epidemiologic studies should adopt a broader perspective, similar to randomized clinical trials.
• Integrating diverse study designs is crucial for advancing public health findings related to MHT and other exposures.