BAKERSFIELD, Calif. -- A new study has found that many cardiologists have more than patient health in mind when they treat their patients.

Concerns about being sued for malpractice influence how often some physicians order potentially unnecessary tests.

Nearly 600 doctors were polled in a survey published in a journal of the American Heart Association. The survey asked about circumstances under which they order cardiac catheterization "for other than purely clinical reasons."

Nearly 24 percent said they recommended the procedure out of fear of malpractice claims.

The survey also showed peer pressure was significant. More than 27 percent of the doctors said they would order the procedure if they believed another physician would order it, even though they personally thought it was unnecessary.

The researchers found practices vary widely around the country and concluded fear of lawsuits results in significant differences in health care use and spending.