When can researchers implement modifications to an IRB-approved research proposal?

The correct choice emphasizes the critical requirement that modifications to an IRB-approved research proposal must receive formal approval from the Institutional Review Board (IRB) before implementation. This is essential because IRBs are tasked with ensuring that any changes do not compromise the safety, rights, and welfare of human participants involved in research. The integrity of the research process and participant protection rests on maintaining rigorous oversight, which includes evaluating any proposed modifications.

Changes could involve adjustments to study procedures, updated informed consent processes, or alterations in participant recruitment strategies, among others. Each of these areas can have significant ethical implications and may affect the risk-benefit ratio of the research, thus they require review and approval prior to enactment.

In contrast, implementing changes without prior IRB approval could lead to ethical lapses and regulatory violations, undermining the foundational principles of ethical research practice.