Response of the Department of Health and Human Services to NBAC's Report 'Research Involving Human Biological Materials: Ethical Issues and Policy Guidance'. Recommendation Regarding Special Concerns About the Use of Unlinked Samples


Recommendation 3. When an investigator proposes to create unlinked samples from coded or identified materials already under his or her control, an IRB (or other designated officials at the investigator’s institution) may exempt the research from IRB review if it determines that

  1. the process used to unlink the samples will be effective, and
  2. the unlinking of the samples will not unnecessarily reduce the value of the research.


The Working Group concurs with the principle in Recommendation 3(a) that caution must be exercised when an investigator proposes to create anonymized samples from coded or identified materials already under his or her control. Unlinking samples reduces risk to the individual who is the source of the sample only if the process of anonymization is effective. The Working Group agrees with NBAC that policies and procedures are needed to ensure that the process of anonymizing samples is effective. The agent to certify that the anonymization process is effective should be the IRB or a designated institutional official.

With respect to Recommendation 3(b), the Working Group agrees with NBAC that unlinking of samples may reduce the potential value of the research. Therefore, IRBs should not discourage research involving use of coded samples when the proposal design includes appropriate protection for subjects and should grant waivers of consent when appropriate. On the other hand, since research with anonymized samples eliminates virtually any meaningful risk to the individuals who provided the samples, the Working Group does not share NBAC’s concern that the effect of anonymization is to “circumvent”7 protections for human subjects. In fact, anonymization provides the highest possible level of protection for human subjects because there are no means to identify the subjects.

There are, however, instances in which anonymization can increase risk to subjects. While research using anonymized samples involves minimal risk to the sample sources, it could, in certain research increase risk of harm to other research subjects. For example, inability to identify the sources of cells or tissues used to develop therapeutic products is a risk to the safety of the recipients of such products in clinical trials.8 These risks may be sufficient to preclude use of materials developed under 45 CFR Part 46 in subsequent clinical investigations subject to 21 CFR Parts 50 and 56, thereby reducing the value of research intended to develop therapeutic materials from human sources. Regardless of the type of research being proposed, careful attention must always be given to assessing the balance of risks and benefits for all participants.

The Working Group has concerns about practical problems that may arise in implementing Recommendation 3(b). This recommendation requires an IRB or institutional official to consider whether anonymization of samples will “unnecessarily reduce the value of the research.9 To consider whether the value of a given project is reduced requires the IRB or institutional official to compare the expected value of the proposal in question with the expected value of a nearly identical but hypothetical study conducted with identified or coded samples.10 This requirement is impossible to meet at worst and at best could go well beyond the expertise of institutional officials responsible for determining whether proposals meet specific criteria provided in federal regulations. In addition, the requirement would expand the mandate or charge of IRBs, for IRBs’ principal mission and focus must be the protection of human subjects in the research that is proposed.

Proposed Action

The Working Group proposes that DHHS explore the feasibility of collaborating with appropriate professional and scientific societies to develop educational materials on methods for the effective anonymization of human biological materials to be used in research. If such an undertaking is determined to be feasible, such materials should be prepared and broadly disseminated to institutions and researchers. Furthermore, institutions receiving federal funds for biomedical research should provide instructions to investigators, where needed, on effective anonymization of human biological materials to be used in research.

View full report


"hbm.pdf" (pdf, 549.86Kb)

Note: Documents in PDF format require the Adobe Acrobat Reader®. If you experience problems with PDF documents, please download the latest version of the Reader®