Changes requested by the IRB following review by expedited procedures or at convened meetings.

• Directive Modifications: Changes requested by the IRB that are editorial or proscriptive (i.e., investigators are given specific text or parameters for addressing the changes); or confirm IRB assumptions. Minor revisions may be re-reviewed by expedited procedures.

• Substantive Modifications: Changes requested by a convened IRB that relate directly to the criteria for IRB approval and require clarification or explanation from the researcher. Substantive revisions must be re-reviewed at a convened IRB meeting.