Do You Need an Amendment to Add or Remove a Research Site?

Can You Add Another Research Site After Your Study Has Been Approved?

Your study is already approved, but another university, hospital, clinic, school, community organization, or research center offers access to participants. The protocol and research questions would remain the same. Can you simply begin conducting the study there?

Usually, the answer depends on much more than the street address. A new site may bring new investigators, participant populations, recruitment arrangements, facilities, data-access practices, institutional responsibilities, local requirements, or additional ethics oversight.

Removing a site can also matter, particularly when the change affects recruitment, sample size, participant follow-up, data custody, or the scientific design. The practical question is therefore what role the site plays in the approved research and what the applicable ethics and institutional arrangements require when that role changes.

Adding or Removing a Research Site May Require an Amendment

A New Location Can Change More Than Where the Research Happens

First Determine Whether You Are Actually Adding a Research Site

The word “site” can be deceptively simple. Researchers may use it to describe almost any place connected with a project, but the ethics and regulatory significance of a location depends on what happens there.

Consider the difference between placing an approved recruitment poster on a community noticeboard and establishing a second location where local staff identify participants, obtain consent, conduct interviews, collect specimens, deliver an intervention, or access identifiable research data. Both involve another location, but their institutional and ethics implications can be quite different.

There is no single universal definition that resolves every case across all research systems. When the distinction matters, describe exactly what the new organization and its personnel will do and obtain a determination under the rules governing your study.

Adding a Site Can Introduce New Institutional Responsibilities

A second site may mean that another institution becomes involved in conducting the research. Depending on the jurisdiction and applicable framework, that institution may require its own authorization, rely on another ethics committee or IRB through an appropriate arrangement, or participate under another multisite review mechanism.

For U.S. cooperative research subject to the Common Rule, specific requirements govern reliance on a single IRB for certain cooperative studies, while exceptions and implementation details apply. OHRP guidance also expressly addresses circumstances in which new institutions are added as sites to ongoing cooperative research. These rules are specific to the U.S. framework and should not be treated as a global model.

A New Site May Change the Participant Population

Suppose a study was approved at a large urban hospital and a rural hospital is later added. The eligibility criteria may remain identical, yet the population available at the new site could differ in age, language, socioeconomic circumstances, access to care, or other characteristics relevant to recruitment, consent, risk, and interpretation.

That does not make the new site inappropriate. It means that “same protocol” does not automatically imply “same ethical context.”

If the site addition also requires new eligibility criteria, translated materials, different recruitment procedures, or different consent arrangements, those are additional protocol changes that should be identified explicitly rather than hidden under the label “add one site.”

Local Context Can Matter

Ethics review is not concerned only with the abstract protocol. Local laws, institutional policies, cultural or linguistic considerations, available resources, privacy practices, participant relationships, and the capacity to manage research-related problems can affect how a protocol operates at a particular location.

This is particularly relevant when research expands across institutions, regions, or countries. A consent procedure suitable in one setting may need adaptation elsewhere. Data-transfer rules may differ. Required institutional permissions may also extend beyond ethics approval.

Adding a Site Can Change Who Has Access to Identifiable Data

A new site may introduce investigators, coordinators, recruiters, clinicians, interviewers, data managers, or other personnel who were not part of the original study. Their access to participant information should be considered.

If data will move between institutions, the study may also need to address secure transfer, storage, confidentiality, data-use arrangements, or institutional agreements. An amendment describing a new site should therefore explain the operational reality rather than merely adding another institution's name to the protocol.

Adding a Site Can Also Change Recruitment

If the new location will identify or recruit participants, consider whether recruitment methods change as well. A hospital may recruit through clinicians, a university through student mailing lists, and a workplace through managers or internal communications. These approaches can create different privacy and voluntariness considerations.

Where the site addition introduces a new way of approaching prospective participants, assess the change to the recruitment method separately rather than assuming that approval of a new location automatically settles every recruitment issue.

Clinical Investigations Can Have Additional Regulatory Requirements

Regulated clinical investigations may have requirements beyond ordinary institutional ethics procedures. For example, FDA guidance for investigational device studies states that increasing the number of investigational sites can require submission and approval of an IDE supplement because expansion may affect the rights, safety, or welfare of subjects. FDA also maintains procedures concerning investigational facilities and IRB approval. These provisions apply to the relevant U.S. device-research framework rather than to human-subjects research generally.

Other regulated studies, sponsors, funders, and jurisdictions may impose different site-activation requirements. Ethics approval should therefore not be assumed to be the only authorization needed before a new site begins research activities.

Removing a Site Is Not Necessarily Just Administrative Housekeeping

Removing a site may appear simpler because research activity is decreasing rather than expanding. Sometimes it may indeed be straightforward. In other cases, removing a site can alter the study substantially.

Consider a two-site comparative study in which one site is withdrawn. The change may affect the research question, sampling strategy, statistical analysis, recruitment target, representativeness, or scientific validity. If participants are already enrolled at the departing site, researchers must also determine how their ongoing participation, follow-up, data, specimens, and records will be handled.

A site closure should therefore answer both an administrative question and a research question: what happens to the institution, and what happens to the study because the institution is no longer participating?

Site Changes Can Trigger Several Amendments at Once

A common mistake is to submit “add Site B” while overlooking everything else that Site B changes. The new site may require revised recruitment materials, additional investigators, translated consent documents, a different enrollment allocation, new data-transfer arrangements, or a larger total sample.

If enrollment will increase as a result, determine whether the approved sample size also needs to change. If participant-facing instruments need adaptation, assess those changes independently as well.

When a Second University Joins an Approved Study

Calling University B “just another place to recruit” would obscure what is actually happening. Once its personnel begin conducting research activities, the ethical and institutional picture may be materially different.

Common Mistakes When Adding or Removing Research Sites

Define What the New Site Will Actually Do Before Requesting Approval

A useful site amendment does more than add or delete an institution's name. Describe the activities that will occur there, the people who will conduct them, the participants who will be recruited, the data that will be accessed or transferred, and the effect on the overall design.

When the proposed change genuinely alters the approved research, follow the applicable process for amending an approved study rather than treating site expansion as a logistical decision made outside the protocol.

Before Adding or Removing a Research Site

Frequently Asked Questions About Changing Research Sites

A Site Change Is About Research Responsibilities, Not Just Geography

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