What is the role of a PI? - High Point Clinical Trials Center

What is the role of a PI?


When I first saw the abbreviation “PI” I paused to think what or who is a PI?–private investigator, physician investigator, personal injury lawyer?  I came to find out that “PI” in the clinical research world stands for Principal Investigator.

In terms of the major players in a clinical research trial,  principal investigators assume ultimate responsibility  for the conduct of a clinical research study.  That being said, an investigator cannot be in all places at all times so research tasks may be delegated to research staff and the investigator must maintain oversight for the conduct of those to whom they delegate these duties.  Again, they are responsible for the ethical conduct and supervision of the trial and will protect the rights, safety and welfare of the volunteers.

Also, an investigator ensures that research volunteers are informed of a study appropriately and that they are aware that the study treatment is being used for research purpose–this is known as informed consent and follows a continuum throughout the study.   If any changes are made to the study protocol, it is the responsibility of the PI to fully inform the volunteers of these changes and offer an option for them to discontinue the study if they wish.  Furthermore, the  PI is the voice for the research site when there are patient care issues that warrant notification of the sponsor or ethics committees (IRB).  .  Again, the rights, safety and welfare of the research volunteers are the number one priority of the investigator.   Medical assessments, efficacy evaluation of the research drug and determining whether the therapy is related to adverse events are further commitments of an investigator. Finally, transparency in terms of providing accurate data are yet another important duty of the PI.

Who can become a PI? 

An investigator does not necessarily have to be a physician or PhD in a particular field, but should be qualified by education, training and experience to assume responsibility for the proper conduct of the trial.  However, the medical care given to, and medical decisions made on behalf of, subjects should  be the responsibility of a qualified physician or, when appropriate, of a qualified dentist.  In terms of experience, the principal investigator should be well versed in the principals found in the International Conference on Harmonisation (ICH) guidelines for Good Clinical Practice (GCP) as well as FDA regulations regarding clinical research.