The study, conducted at seven clinical centers among 875 healthy women aged 45 to 64, is sponsored by the National Heart, Lung and Blood Institute.
Studies of the drug were being conducted at 17 centers across the country.
The study was conducted at 32 centers around the country.
The study, conducted at 25 medical centers, included 969 women with recently diagnosed cancer in one breast and a normal mammogram on the other.
It will involve 3,000 heart attack patients and will be conducted at eight clinical centers in the United States.
The vaccine tests were conducted at three medical centers.
Phase III trials are currently being conducted at 17 medical centers across the United States.
This most carefully designed study of hormone replacement was conducted over a three-year period at seven clinical centers among 875 healthy women from 45 to 64 years old.
Financed by the National Institutes of Health, the $628 million research project is being conducted at 40 medical centers nationwide.
The study was conducted at 27 medical centers among 3,234 high-risk participants who had already begun to show an impaired ability to regulate blood sugar.