When patients are harmed, but are not wronged: ethics, law, and history.

Iatrogenic injury-injury caused unintentionally by medical treatment-breaks the oldest and most famous rule of medical ethics: primum non nocere, or above all, do no harm. Medical malpractice law, however, focuses on whether an injury was caused by negligence, not on whether an injury was iatrogenic. Iatrogenic injury inflicted without negligence is a common pattern in medical malpractice lawsuits; it is likely the pattern of Jacobs v Cross (Minnesota, 1872), in which Dr W. W. Mayo testified as an expert witness. As a matter of law, the doctor defendants should win all those lawsuits, for iatrogenic injury inflicted without negligence is not a legal wrong in the United States and has not been considered a legal wrong for hundreds of years. However, the medical ethics applicable to doctors' duties to report incompetence in colleagues, including those who inflict excessive iatrogenic injury, have developed dramatically over time. In 1872, the ethical codes in the United States exhorted doctors not to criticize another doctor, even if incompetent. Today, doctors in the United States are ethically required to report an incompetent colleague.