Advance directives, substituted judgment, and the best-interest standard all have limitations that constrain their usefulness in making medical decisions for patients who cannot choose for themselves.
Advance directives do not always resolve questions about the best care for patients who no longer have decision-making capacity; physicians and patient surrogates can take alternative approaches to arrive at the best care decision.
Quality improvement initiatives in clinical medicine are part research and part patient care and pose challenges to traditional forms of ethical oversight.
Even if they are not sick, people in quarantine are still patients; the physician is responsible for their well-being and may find that it is necessary to advocate for them.