The bit you've quoted is intended to clarify that "about whom" means the subject is the patient, even if the researcher gets the information indirectly through the patient's doctor. Earlier in the document you linked, it states:
> If for the purpose of a research study [...] An investigator [...] interacts with a living individual, [...] Then The research likely involves
human subjects.
What's up for debate here is whether this research qualifies for one of the specific exemptions in the regulation. The general definition in the regulation is broad enough to include all interaction with living humans that produces information used for the study, and is only narrowed by later enumerated exemptions.
> If for the purpose of a research study [...] An investigator [...] interacts with a living individual, [...] Then The research likely involves human subjects.
What's up for debate here is whether this research qualifies for one of the specific exemptions in the regulation. The general definition in the regulation is broad enough to include all interaction with living humans that produces information used for the study, and is only narrowed by later enumerated exemptions.