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.
The practice of banking sperm from adolescents about to undergo chemotherapy is not universal, which lends support to the argument that parental consent be required for the intervention.
Writing a case study of a psychiatric patient may change the patient-physician dynamic even if the patient consents to be written about. And when the patient is a minor and consent must involve her parents, the process becomes even more complicated.