A person who actually and principally carries out the action. Need not be the principal responsible actor, e.g. a surgery resident operating under supervision of attending surgeon, and may be the patient in self-care, e.g. fingerstick blood sugar. The traditional order filler is a performer. This information should accompany every service event.
\nhttp://terminology.hl7.org/CodeSystem/v3-ParticipationType
where concept is-a PRF