Answer:
Must occur within 12 months of the approval date.
Explanation:
According to the Institutional Review Board (IRB) guidelines, for effective protection of research subjects and to ensure researchers abide by ethics, continuing review of an approved and ongoing study posing more than minimal risk that was initially approved by a convened IRB must occur within 12 months of the initial approval date so as to determine if the research can continue or if it must undergo full board review.