Analysis: How the new US malpractice standard puts evidence-based ‘reasonable care’ over customary practice

Editor's Note

A February 26 letter in JAMA Network reported a revised legal standard for medical negligence in the US, shifting from traditional reliance on customary practice toward a more patient-centered, evidence-based definition of “reasonable care.” The American Law Institute (ALI) updated its framework in 2024, retaining elements of prevailing medical practice but clarifying that a court may deem certain customs inadequate if they fail to meet contemporary standards of competence.

Under the new standard, reasonable care is defined as “the care, skill, and knowledge regarded as competent among similar medical providers” in comparable circumstances—a subtle yet significant departure from “customary” care. This pivot effectively moves from ‘what everyone else is doing’ to ‘what everyone else knows (or should know) to do,’ inviting courts to incorporate evidence-based clinical guidelines into malpractice considerations. While legitimate, authoritative guidelines carry weight under the revised framework, failure to follow them is not automatically deemed negligence.

According to a March 11 analysis in the New England Journal of Medicine (NEJM), the ALI’s revised standard may eventually reduce defensive medicine by acknowledging that contemporary, evidence-based practices should inform what is considered reasonable. The NEJM piece highlights how the legal definition of malpractice has long centered on whether the care provided was consistent with the “custom of the profession.” Now, the new emphasis on evidence-based guidelines may protect clinicians who base care decisions on reputable clinical data, rather than on entrenched but outdated norms.

An example cited in the analysis from two decades ago illustrates this shift: A physician who elected not to perform a prostate-specific antigen test, following evidence-based guidelines at the time, was sued when a subsequent physician discovered the patient’s advanced prostate cancer. The lawsuit ended in favor of the patient, partly because the trial portrayed evidence-based care as inferior to widespread clinical custom. The NEJM analysis suggests that under the new ALI standard, a verdict dismissing guideline-based care would be far less likely.

Because malpractice law is almost entirely state-based, changes may be gradual. Still, experts believe the ALI’s revision marks a meaningful step toward aligning legal and clinical frameworks, potentially reducing liability fears around adopting new, evidence-based approaches and gradually phasing out outdated practices that persist only due to local custom.