The physician-patient relationship is not a partnership wherein which the parties should strive to reach an outcome that best suits the interests of the partners. Rather, the physician-patient relationship represents an ethically and legally recognized fiduciary relationship wherein one party (the physician) is charged with looking after the health care interests of the other (the patient).
In the context of this physician-patient fiduciary relationship, it would be unethical—and antithetical to the very concept of a fiduciary relationship—for a physician to seek a mutually beneficial outcome or to try to meet shared objectives. Rather, it is the physician’s duty to help the patient choose, from among available ethical options, a management course that the patient deems to be the best for themselves.
Shared decision making was once offered as a contrast to a system in which physicians made decisions for their patients, with little or no patient input. The sharing in this context was done by physicians who took it upon themselves to share their then-actual (but never legal or ethical) decision making power with their patients. This sharing by physicians was certainly an improvement upon the then status quo of autonomous and paternalistic decision making by physicians. But we now know better than that: the patient has all the natural and legal powers to make decisions for themselves, and the default mode is always autonomous, although physician-supported, decision making by the patient. (True, the patient may appoint the physician co-decision maker or surrogate decision maker, but this should be done only at the request of the patient or be offered to the patient if the patient feels “stuck” or incapable of making decisions on their own).
Shared decision making as an ideal is contaminated with traces of paternalism and is a once-sacred cow that needs to be put out to pasture as soon as possible. The default mode is, and always was (or should have been!), patient autonomy.