Research investigators have unique responsibilities to protect human subjects participating in clinical trials. Investigators must use their clinical and professional judgment in areas that are not readily reviewed by institutional review boards (IRBs).
The investigator must be able to respond affirmatively to 3 questions regarding the research protocol
(1) Does the protocol ask an important enough scientific question to justify the required resources of the investigators and research participants? (2) Is there a reasonable likelihood that the study can be completed as designed? and (3) Is it likely that the completed study will answer the research question?
In the special setting of a randomized intervention study, the investigator must be certain that there is clinical equipoise regarding the alternative treatment assignments. Clinical equipoise implies that the scientific community is in a state of genuine uncertainty regarding the relative merits of different interventions, including, in the special setting of placebo-controlled trials, no intervention. Only the investigator can make an educated assessment of this situation. Even if clinical equipoise exists, if the investigator has a deeply held personal bias regarding treatment alternatives, participation as an investigator is unwise.
During the conduct of the study investigators also have important initial and ongoing responsibilities regarding the consent of research participants. Although IRBs review consent forms, the process of consent is seldom overseen. The investigator must determine whether, in his or her best judgment, the potential research subject has made a voluntary and informed decision to participate in the study. If the investigator feels that this condition is not met, even if the person is willing, the person should not be enrolled. In addition, the investigator is responsible for advising research participants of study developments that may bear on continued consent to participate in the research. This is not merely a factual reporting of events but requires providing the information in an individualized context.
Although IRB review of protocols enhances the likelihood that research subjects will be protected, investigators continue to need to exercise thoughtful judgment in areas that are not easily reviewed by oversight groups.
Kieburtz K. Conduct of Clinical Trials: The Principal Investigator's Perspective. Arch Neurol. 2002;59(2):325. doi: