Co-Enrollment Prevention (CEP) Frequently Asked Questions

Requirements and Resources

The requirements and supporting information can be found in the DAIDS SCORE Manual in the Screening, Enrollment, and Unblinding of Participants section.

Additional materials can be found as appendices to the Screening, Enrollment, and Unblinding of Participants section of the DAIDS SCORE Manual  and include the following:
  • Guidance document and risk assessment questions
  • Co-Enrollment Prevention SOP Template
  • Template Letter to the IRB
  • Related frequently asked questions (FAQs)

Site staff can always reference the SCORE manual or the recording of the Co-Enrollment Prevention Webinar that will be posted on the HANC website.


For the purposes of DAIDS research, co-enrollment and dual enrollment are synonymous. These terms can refer to the enrollment of the same participant in the same study at multiple sites, which is never allowed. They can also be used to refer to enrollment of the same participant in more than one study, which may be allowed depending on the protocol.

It depends on the protocol and the study agents being evaluated in each protocol. If co-enrollment is allowed, it will usually be specified by the protocol, but the determination is up to the study team for each protocol. Sites should follow up with their OCSO PO or the medical officer for the protocol if unsure what is allowed. A site’s SOP should specify which protocols their co-enrollment prevention system will cover.

The guidance document provided by DAIDS has a set of questions that can be reviewed to help determine the site’s level of risk. The more protocols a site conducts, and the more sites that conduct similar research in the same metro or catchment area, the higher the risk will be. Higher risk sites should consider implementing a more robust plan and including other clinical research sites (DAIDS and non-DAIDS) in the same area when possible.

Co-enrollment Prevention (CEP) SOP Development

Sites are not required to use the SOP template provided by DAIDS. However, reviewing the DAIDS provided template can provide insight into what a robust SOP might include.

Continue to follow the process, but please confirm that current process meets all the requirements in the SCORE manual and make any necessary changes. Please also make sure the process is submitted to the local IRB/EC for approval.

If another site SOP also includes details about how co-enrollment will be prevented, then a separate SOP for Co-enrollment prevention (CEP) is not needed. Sites will need to submit this SOP to the IRB/EC or other institutional body for review and approval.

If an SOP that includes CEP does not already exist, or does not comply with the current requirements, it may be worthwhile to create a separate SOP, just for ease of submitting this for IRB/EC review and getting approval. Sites that have this process included in other SOPs should be prepared to explain this to monitors and show them where the procedure is located, as well as the IRB/EC approval for that procedure/document. It is acceptable to combine CEP and Age & Identity Verification within one SOP.

Yes, a CRS can choose to use an overarching CTU SOP, or create its own SOP. This is up to the discretion of the CRS and CTU and the decision should be based on the populations that each CRS serves. If a CTU SOP is used as a starting point, each CRS must have the opportunity to review and make revisions as required to make sure it fits within their own unique workflow and addresses situations unique to potential participants of the site.

The SOP requirement is applicable to all CRSs conducting DAIDS sponsored research within the DAIDS Clinical Trials Networks. Please contact the OCSO PO if there are questions about whether the requirement applies to a particular site.

Please make sure to consult with local community groups as to acceptable practices for inclusion in the SOP. Please submit the SOP to the local IRB/EC or other local institutional body and file their approval before implementing the SOP.

The SOP does not need to be submitted to DAIDS for review. For any questions relating to content, please refer to the guidance in the manual, the SOP template provided or reach out to the OCSO PO assigned to the site.

Site staff develop the SOP in conjunction with community groups/CAB and any other relevant institutional bodies. Once finalized, submit to the local IRB/EC or other relevant institutional body for review and approval. This will ensure that a local body tasked with the oversight of participant safety and wellbeing is reviewing the procedure and verifying that it is acceptable within the context of local and in-country laws or regulations. DAIDS has provided an introductory letter template which explains the rationale for requesting review and this can be edited to suit individual site needs when submitting the SOP for review.

If the IRB/EC has declined to review or approve the SOP, please request documentation of this for filing at the site with the SOP. Consider finding an alternate institutional body focused on participant welfare to review the SOP.

Co-enrollment Prevention (CEP) SOPs – timeline

As of October 1, 2021, any current active or in development sites will have 3 months to develop their CEP SOP/process and obtain approval from the IRB/EC or institutional body following the implementation of the requirement.

As of January 1, 2022, any new sites being developed will need to put the SOP in place as part of the OCSO Site Activation requirements.

Once final approval of the SOP(s) is received from the IRB/EC or other institutional body. If the IRB/EC has declined to review or approve the SOP, please request documentation of this for filing at the site and consider submission to an alternative institutional body focused on participant welfare. After all approvals are received and on file, site staff are to be trained on the SOP prior to its implementation.

Plan to implement this SOP for ongoing protocols as soon as it is approved by the IRB/EC or other institutional body. The site may need to create a note to file for ongoing protocols that indicates when and how the new SOP was implemented for participants in those studies. The SOP should be implemented for any new protocols that begin after the date of the SOP finalization.

Communication with Community/Participants

Assure participants that preventing co-enrollment is an important step in ensuring their safety, as well as ensuring the scientific objectives of a study can be achieved. The IRB/EC-approved consent for screening and study participation may need to be updated to inform the potential participants about this requirement (if required by IRB/EC, and if an electronic or biometric system is used). Sharing information with participants on how their data is being used, stored, and protected can also help ease participant apprehension.

Introduce the concept of co-enrollment prevention checks to study participants while the SOP is being developed, before you implement the new process. Assure participants of the site’s commitment to protecting their safety and wellbeing and educate them on how the new process will strengthen that commitment.

Consult the local CAB for recommendations on how best to communicate any new processes before implementation and seek their assistance in communication efforts.

U.S. Health Insurance Portability and Accountability Act (HIPAA)

See our Co-enrollment Prevention and HIPAA FAQ


Starting in 2022 PPD monitors will verify that an SOP is in place along with documentation of its approval from the IRB/EC or other institutional body.

Sites are expected to use existing core or protocol funds to cover the cost of purchasing or implementing a co-enrollment prevention system. Sites should also consider cost sharing with other sites in the same local catchment area, if feasible.
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