The phrase “standard of care” has a different meaning across professions. For doctors, the standard of care is patient-centric. Sir William Osler wrote, “Medicine is a science of uncertainty and an art of probability.” The medical standard of care is ideally a consensus of approved treatment modalities and the accepted variations inherent to the “art of medicine.”
The law does not recognize “art” in medical practice but does recognize that the process is sufficiently complex that doctors should be involved in determining when care was appropriate. The legal standard of care involves “multiple moving targets” that evaluate “the degree of care and skill that a physician or surgeon of the same medical specialty would use under similar circumstances.” Attorneys employ a process-centric hindsight evaluation to define the medical standard of care, comparing the process of what was done with what could or should have been done.
Government entities and insurance companies view the standard of care as an end-result evaluation tool. To these entities, care is defined in outcome-centric terms. The “standard of care” is that care most likely to produce desired outcomes, evaluating overall cost management and patient health.
Patient-Centric Standards: Internal Regulation by Healthcare Providers and Professional Associations Defines a Standard of Care
Due to the scientific complexity underlying medical care, and the belief that doctors want what is best for their patients, U.S. society has largely allowed doctors to judge which care is appropriate. Patient-centric standards consider the range of available treatments, situational probabilities, patient desires, and uncertainties of unknown and unknowable patient factors.
Without a central governing medical body, the classification of care as appropriate or inappropriate falls on local or national groups of physicians. These groups enforce their decisions through varying internal regulation mechanisms, such as licensure requirements and peer review. However, even the internal regulation mechanisms created by physicians fail to identify a single measure against which physicians will be judged. Instead, internal regulation may use any combination of (a) customary care practice standards, (b) evidence-based standards, or (c) clinical practice guideline standards.
 BEAN WB. SIR WILLIAM OSLER: APHORISMS, 129. https://store.acponline.org/ebizatpro/images/productimages/books/sample%20chapters/QuotableOsler_Ch02.pdf. (last visited March 12, 2015).  Richard Gober, Texas State AAG, Conversation  Garner BA, ed. Black's Law Dictionary. 7th ed. St. Paul, MN: West Group; 2010.  Maxwell J. Mehlman, Professional Power and the Standard of Care in Medicine, 44 Ariz. St. L.J. 1165, 1225-26 (2012).  James C. Mohr, American Medical Malpractice Litigation in Historical Perspective, 283 JAMA 1731, 1732 (2000).