Issues to debate on the Women's Health Initiative (WHI) study. Hormone replacement therapy: an epidemiological dilemma?

In July 2002 the data of the prematurely stopped Estrogen plus Progestin study of the Women's Health Initiative (WHI) were presented in the Journal of the American Medical Association. The results of the Heart and Estrogen/Progestin Replacement Study (HERS/HERS II) were published in the same issue. The results of WHI for healthy postmenopausal women often are interpreted to be in analogy with the HERS/HERS II results for postmenopausal women with established coronary heart disease. As a result of HERS/HERS II and WHI, use of HRT in general became questionable. This is an unjustified judgement of HRT in general. This synoptic review and criticism of both studies will show the methodological weaknesses and their consequences and the reasons for limited generalizability of the study results from WHI and HERS/HERS II on normal HRT users.