From OHRP on Legally Informed Consent for Research with Children
The IRB must determine, to the extent required by 45 CFR 46.116, that adequate provisions are made for soliciting the assent of the children -- when in the judgment of the IRB the children are capable of providing assent -- as well as the permission of the parents (45 CFR 46.408). Permission means the agreement of parent(s) or guardian to the participation of their child or ward in research (45 CFR 46.402(c)).
By regulatory definition, children are “persons who have not attained the legal age for consent to treatments or procedures involved in the research, under the applicable law of the jurisdiction in which the research will be conducted” (45 CFR 46.402(a)). In the United States the legal age of adulthood is a matter of state and local law. This means that who is legally considered a child may vary from state to state; in a large majority of states 18 years of age is the legal age of adulthood, but this is not true in every state, locality, or territory. State law also may address specific circumstances in which a person younger than the age of adulthood is legally authorized to consent to medical procedures: for example, some states allow children younger than the legal age of adulthood to consent to the provision of contraceptive services. Certain states provide a mechanism for the emancipation of minors, through which a child younger than the legal age of adulthood may gain certain civil rights, which might include the legal ability to consent to research participation.
The definition of children also takes into account the particular interventions or interactions involved in the proposed research (e.g., surveys, blood tests). For example, in some places individuals who are 16 years of age may legally consent to certain clinical interventions or interactions. If the involvement of human subjects in a proposed research activity consists of these interventions or interactions, then those individuals may be considered as adults for that purpose. If a proposed activity includes an intervention or interaction for which the subject has not yet reached the legal age of consent, however, that person must be considered a child.
Under 45 CFR 408(b) the IRB may find that the permission of one parent is sufficient for research to be conducted under 45 CFR 46.404 or 45 CFR 46.405. Where research is conducted under 45 CFR 46.406 or 45 CFR 46.407, permission must be obtained from both parents unless one parent is deceased, unknown, incompetent, or not reasonably available, or when only one parent has legal responsibility for the care and custody of the child.
Although the regulations state that children are unable to provide legally effective informed consent to participate in research, some might be able to give their assent. Assent means a child’s affirmative agreement to participate in research. Mere failure to object should not, absent affirmative agreement, be construed as assent (45 CFR 46.402(b)).
If the IRB determines that the capability of some or all of the children is so limited that they cannot reasonably be consulted regarding assent, or that the intervention or procedure involved in the research holds out a prospect of direct benefit that is important to the health or well-being of the children, and is available only in the context of the research, the assent of the children is not a necessary condition for proceeding with the research. Even where the IRB determines that the subjects are capable of assenting, the IRB may still waive the assent requirement under certain circumstances in accord with 45 CFR 46.116 and 45 CFR 46.408(a).