CHICAGO -- Prescriptions for hormone supplements have plunged by one-third in the United States since a study was abruptly halted because of evidence the pills raise the risk of breast cancer, heart disease and other illnesses in postmenopausal women, an analysis found. In the year after the July 2002 announcement about the risks from estrogen-progestin pills, U.S. prescriptions for most types of hormone therapy dropped 38 per cent, reversing a seven-year trend, according to the report in today's issue of the Journal of the American Medical Association.

Data published in the journal last June showed a 32-per-cent drop in hormone replacement therapy prescriptions in Ontario in the six months following the announcement that the Women's Health Initiative study was ending early because of the identified risks.

Based on data through July, the U.S. researchers estimate that prescriptions for hormone treatments including estrogen-progestin pills will total 57 million in 2003, compared with 91 million in 2001.

About six million American women used the combined pills in 2001 and an estimated 14,500 cases of heart disease, breast cancer, stroke and blood clots were due to estrogen-progestin use that year, the researchers said.

They estimated the number of such illnesses dropped to 6,500 in 2003, a 56-per-cent drop from 2001.

"A very large population uses these drugs and has been positively affected by the changes in practice that have come about," said Dr. Randall Stafford of Stanford University's Prevention Research Center, an author of the new analysis.