Doctor bias plays role in prescribing hormone replacement therapy

Doctors reluctant to prescribe hormone-replacement therapy for menopausal women may be victims of biased thinking.

A recent study on the decision-making of gynecologists and obstetricians in prescribing hormones for menopausal women shows that even some well-informed physicians may choose not to recommend hormones when they probably should. The study by Jonathan Baron, Ph.D., Penn professor of psychology, is scheduled to appear in the October/November issue of the journal Medical Decision Making.

Jonathan Baron, Ph.D., claims that some physicians may not prescribe hormone replacement therapy even when they probably should.

"I'm interested in decision-making and the principle of doing the most good," Baron said.

In theory, that's what most doctors also care about -- making the best decisions for their patients' good health.

But biases cause doctors to lose sight of what course will do the most good for the most people. Some doctors, for example, are "just interested in preventing breast cancer," Baron said, but they are "not worried about preventing heart disease and osteoporosis." But breast cancer claims fewer victims than the other diseases. Those doctors have a proportionality bias.

"Most studies of hormone replacement therapy have concluded that the benefits outweigh the risks for most women," Baron's article states. Even with the most recent studies showing the limits of hormone therapy in preventing heart disease, Baron says the benefits still easily outweigh the risks.

One of the things that inspired Baron to investigate hormone replacement therapy was the reluctance of physicians and parents to administer the DPT (diphtheria-pertussis-tetanus) vaccine.

Baron found that in some cases doctors' reluctance to prescribe hormone-replacement therapy was similar.

"The DPT vaccine causes an infection sometimes, the same infection that it also prevents," Baron said. "Very few kids get the infection from the vaccine, and many more are helped."

But doctors and parents lose sight of the greatest good when there's even a small chance of harm from the act of administering the vaccine.

"They don't want to be responsible for something caused by an action," Baron said. "They don't mind if a greater harm results from their act of omission."

The result of doctors' and parents' reluctance, said Baron, was a couple of whooping cough epidemics, one in Japan and one in Great Britain.

Similarly, doctors fear prescribing hormone replacements just in case taking action might trigger breast cancer, even though the numbers of probable victims is by far outweighed by the numbers who would be saved from other life-threatening diseases.

Which is not to say that the doctors didn't have some rational reasons for committing acts of omission -- the fear of lawsuits.

To determine which biases might interfere with prescribing hormone-replacement therapy, Baron sent a questionnaire to 1,000 gynecologists in the United States and received 328 replies. Although he found that the effects of bias were small, he noted that they "existed despite the high level of knowledge of our respondents and despite their overall faborable attitutde toward" hormone replacement therapy.

Baron also found that older doctors had less favorable attitudes toward hormone replacement, but that the doctor's sex was unrelated.

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Originally published on September 3, 1998