For example, doctors who receive income from referring patients for medical tests have been shown to refer more patients for medical tests. This practice is proscribed by the American College of Physicians Ethics Manual
Fee splitting and the payments of commissions to attact referrals of patients is considered unethical and unacceptable in most parts of the world. It is tolerated, though, in some areas of US medical care.
Vendor relationships
Studies show that doctors can be influenced by drug company inducements, including gifts and food. Industry-sponsored Continuing Medical Education (CME) programs influence prescribing patterns. Many patients surveyed in one study agreed that physician gifts from drug companies influence prescribing practices. A growing movement among physicians is attempting to diminish the influence of pharmaceutical industry marketing upon medical practice, as evidenced by Stanford University's ban on drug company-sponsored lunches and gifts. Other academic institutions that have banned pharmaceutical industry-sponsored gifts and food include the University of Pennsylvania, and Yale University.
Treatment of family members
Many doctors treat their family members. Doctors who do so must be vigilant not to create conflicts of interest or treat inappropriately.
Sexual relationships
Sexual relationships between doctors and patients can create ethical conflicts, since sexual consent may conflict with the fiduciary responsibility of the physician. Doctors who enter into sexual relationships with patients face the threats of deregistration and prosecution. In the early 1990's it was estimated that 2-9% of doctors had violated this rule.