Informed consent key to patient counseling on HRT use. (Dealing with WHI Fallout).

BIG SKY, MONT. -- History will view the early halt of the combination hormone replacement therapy arm of the Women's Health Initiative as "a defining moment' in the careers of most ob.gyns., Dr. Eric J. Bieber predicted.

"I can't imagine another situation where we'll see 4-5 million women affected by a single study I still don't know that we have any sense of what the fallout is going to be," Dr. Bieber said at an ob.gyn. update sponsored by the Geisinger Health System.

When the National Institutes of Health stopped the estrogenplus-progestin arm of the Women's Health Initiative (WHI) due to increased rates of breast cancer and cardiovascular events, compared with placebo, the effect on physicians' practices was chaos, said Dr. Bieber, chairman of ob.gyn. at Geisinger Medical Center in Danville, Pa.

"We have the largest rural HMO in the country It was truly a disaster as the study came out. The number of phone calls was overwhelming. We're still trying to work through it," he said.

Dr. Bieber has observed three distinct reactions among postmenopausal women who were on hormone replacement therapy (HRT) at the time of the WHI announcement. One group stopped taking their medication that very day and will probably never again take a sex steroid, even topically.

A second group today remains on HRT but is very frightened and uncertain about what to do. The third group consists of patients who remain steadfast in their compliance with HRT, Dr. Bieber said.

It's crucial now that physicians sit down with patients in the latter two groups for a rational talk about the meaning of the WHI and the pros and cons of HRT.