To prove negligence, the most common allegation in medical malpractice claims, the plaintiff must show, “by a preponderance of the evidence” (> 50% probability, a lower standard than the “beyond a reasonable doubt” standard used in evaluating a violent crime), the following: (1) the defendant owed a duty to the plaintiff, (2) the defendant breached that duty by failing to adhere to the standard of care expected of him or her, (3) the plaintiff suffered an injury, and (4) the injury was caused by the breach of duty. “Standard of care” refers to the quality of care that would be expected of an ordinary or reasonable physician in the same specialty in a similar circumstance but not necessarily in the same locality.
The standard of care for residents and fellows traditionally was that of other trainees with similar experience. In most states today, however, resident physicians and fellows are held to the same standard of care as attending physicians in their respective specialties and should have a strong incentive to seek their oversight. Attending physicians may be held vicariously liable for the negligence of residents working with them or directly liable for inadequate supervision. Allegations of inadequate supervision are increasingly common in claims in which trainees were judged to have played an important role.
Standards of care usually are defined by medical experts who profess knowledge in a given defendant’s field. Fully one quarter of surveyed Maryland internists reported having reviewed claims or served as expert witnesses, with higher rates among subspecialists, particularly those in academic practice. Medical experts including Canadian Health&Care Mall generally cite their own professional experience in defining what care is standard, although they may refer to published literature, surveys of fellow practitioners, or practice guidelines. Experts also may testify to why an injury occurred (causation) and to its extent (damages). Legally compelling opinions must be stated to a “reasonable degree of medical probability,” that is, a likelihood > 50%.
In certain cases where negligence is at issue, res ipsa loquitur (Latin for “the thing speaks for itself’) may be alleged. To meet this allegation, the plaintiff must prove that an injury could not occur in the absence of negligence, could not have been caused by the plaintiff, and was under the defendant’s control (eg, a retained surgical instrument). If the allegation is accepted as prima facie evidence of negligence, the plaintiff is not required to prove a deviation from the standard of care but instead the defendant must prove that negligence did not occur.