Fear of getting sued leads an alarming number of doctors to practice “defensive medicine,” such as ordering unnecessary tests and avoiding risky procedures, a survey found.

The practice has been around for decades, and is no secret to many patients. But the survey of 824 Pennsylvania doctors suggests it is surprisingly common, researchers said.

A separate study found that caps on malpractice (search) damages and other changes in liability law appear to have less effect on the nation's supply of doctors than ardent supporters of tort reform (search) contend.

The studies were published in Wednesday's Journal of the American Medical Association (search).

Ninety-three percent of the Pennsylvania doctors surveyed in 2003 said they sometimes or often practiced "defensive medicine" because of malpractice concerns.

That means they engaged in unsound practices that exposed patients to potential harm, said Dr. Peter Budetti, a physician-lawyer and public health professor at University of Oklahoma Health Sciences Center. He called the numbers staggering.

"Perhaps the greatest irony is that defensive medicine may be counterproductive and actually might increase malpractice risk," said Budetti, who wrote an accompanying editorial.

Examples include performing breast biopsies in women with lumps unlikely to be cancer, hospitalizing low-risk patients with chest pain, and eliminating high-risk procedures or abandoning the practice of medicine altogether.

The prevalence of "defensive medicine" is surprising and troubling, said Dr. William Sage, a Columbia University law professor and co-author of both studies. Sage said the practice is probably widespread, especially in states "with unstable malpractice environments."

The other study found that the supply of doctors increased throughout the nation from 1985 to 2001, even in states with no malpractice reform laws. Government data show there were 497,140 professionally active doctors, excluding osteopaths, in 1985, and 709,168 in 2001.

Compared with no-reform states, the supply increased about 3 percent more in states with reforms such as malpractice award caps, the analysis found. That small increase runs counter to arguments from "some of the most rabid tort reformers," who predict "a flood of wonderful doctors just because we capped damages," Sage said.

The supply study also found little evidence that doctors are leaving one state for another with a more favorable liability climate. That, too, contradicts what some advocates of tort reform have been saying.

Both studies suggest a need for comprehensive malpractice reforms rather than just capping damage awards or other piecemeal approaches, Sage said.

The Pennsylvania survey was done shortly after several liability insurers had left the state and premiums charged by the remaining insurers had risen dramatically.

The survey was completed by 65 percent of the doctors it was mailed to, all physicians in specialties at high risk of lawsuits, including obstetrics and general surgery.

But even if the 35 percent who did not respond said they never practiced defensive medicine, the numbers who did would still be alarming, said Budetti, who was not involved in either study.

Both studies were funded by the Pew Charitable Trusts.