The use of combined estrogen-progestin replacement therapy.

The evaluation of innovations which use old technology poses different problems than does the evaluation of new technologies. The main necessity is the targeting of its use rather than the technology itself. The need to evaluate the extent of use and its problems is illustrated by the example of progestin use among menopausal and postmenopausal women in the United States. There progestins are not officially approved for use in menopause, even though they have been on the market for a long time with other indications. Estrogen-replacement therapy was widely used from the early 1960s until 1975, when the claim that estrogens cause endometrial cancer notably decreased their use. The use of estrogens increased again in the early 1980s, and one reason for this revival was the claim that progestins offered protection against endometrial cancer. When recommendations for combined estrogen-progestin therapy have been made, other health effects have been ignored. Two consensus conferences as well as the drug control authority have recommended against combined estrogen-progestin therapy until further research is completed. Absence of good research, specialization in medicine, and advantages for prescribers and the drug industry may have contributed to the wide use of this unassessed treatment. Possible solutions for prevention of the diffusion of these kinds of innovations are discussed.