MHRA GCP guide (11.2.1) states "A PI must1 be an authorised health care professional, however they do not have to be a medically qualified doctor, although it should be noted that there are a number of trial related activities that are required2 to be performed by a medically qualified doctor (such as eligibility, decision to dose and safety reviews)." The MHRA quotes a Regulation requiring this, schedule 1, part 2 (11) of SI 2004/1031. Therefore decision to dose must be conducted by a medically qualified doctor.

FDA final Guidance for Industry Investigator Responsibilities, Protecting the Rights, Safety, and Welfare of Study Subjects (Oct 2009), states "In all cases, a qualified physician (or dentist) should be responsible for all trial-related medical (or dental) decisions and care". This is also a theme shared by EU GCP Inspectors but specification as to what exactly are these "medical decisions" varies. Some of them do require eligibility, decision to dose and safety reviews to be performed only by a medically qualified doctor.