Amendments, Continuing Review, and Adverse Event Reporting

IRB approval is not a one-time event. Once your study is active, you take on ongoing reporting obligations: changes to the protocol must be reviewed before implementation, annual or periodic continuing reviews may be required, adverse events and unanticipated problems must be reported on fixed timelines, and study closure requires its own paperwork. This guide explains what to submit, when, and why.

The core regulatory framework lives in 45 CFR 46.103, 45 CFR 46.108, and 45 CFR 46.109. FDA-regulated research layers in additional obligations from 21 CFR 50 and 21 CFR 56 that this guide notes where relevant.

Amendments: when to submit

Any change to an IRB-approved study generally requires IRB review before implementation. Common triggers:

• Changes to study procedures (adding a visit, a new instrument, a new biospecimen collection)
• Changes to the consent form or recruitment materials
• Changes to the study team (adding or removing personnel)
• Changes to inclusion or exclusion criteria
• Changes to the sample size
• Addition or removal of study sites
• Changes to data management, storage, or sharing
• Changes to funding source

How to submit an amendment

Most IRBs require:

• A cover memo summarizing what changed and why
• Tracked-changes and clean versions of every modified document
• Updated consent forms with a new version date
• A plan for re-consenting currently enrolled participants if the changes affect risk, benefits, or procedures

Minor amendments (administrative changes, typos, study team updates) can often be approved by the chair under expedited procedures. Substantive amendments — especially those changing risk — typically return to the same review level the original protocol received. See full board and expedited pathways.

Continuing review

Under the 2018 revised Common Rule, continuing review is not required for studies reviewed under exempt procedures, for most expedited studies, or for studies that have progressed to data analysis only with no further participant interaction (45 CFR 46.109(f)). Continuing review is still required for:

• Full-board-reviewed research, at intervals determined by the IRB but no less than annually
• Any study the IRB specifically determines requires it, based on risk
• FDA-regulated studies, per 21 CFR 56.109

How amendments differ from continuing reviews

Amendments and continuing reviews serve different purposes and should not be confused.

Continuing review submissions typically require:

• Current enrollment numbers (screened, enrolled, withdrawn, completed)
• Summary of adverse events and unanticipated problems
• Any protocol deviations
• Updated literature that affects risk/benefit
• Current approved consent form
• Any complaints from participants
• Investigator statement that the study continues to meet approval criteria

Adverse events and unanticipated problems

These terms are commonly confused, but they are distinct categories with different reporting thresholds.

Adverse event

Any untoward medical occurrence in a participant — regardless of causal relationship to the research. Not every adverse event is reportable to the IRB; the determining factor is whether it is unexpected and related to the research.

Unanticipated problem involving risks to subjects or others (UPIRTSO)

Per OHRP guidance, a problem is unanticipated if it is unexpected (given the study procedures and participant population), related or possibly related to participation, and suggests the research places subjects or others at greater risk than previously recognized. UPIRTSOs must be reported to the IRB.

Typical reporting timelines

Exact timelines vary by institution. Check your local IRB's reporting policy and write them into your protocol's safety monitoring section.

FDA-regulated research

IND and IDE studies carry additional reporting to the FDA and sponsor on top of IRB reporting. Serious adverse events that are both unexpected and possibly study-related must typically reach the FDA within 15 calendar days, or 7 calendar days for fatal or life-threatening events. Coordinate with your study sponsor.

Study closure

A study is closed when enrollment has ended, data collection with participants is complete, and data analysis involving identifiable data is also complete. Closure is not optional — IRB approval continues to carry obligations until the study is formally closed.

Closure submission typically includes

• Final enrollment numbers
• Summary of adverse events and unanticipated problems over the life of the study
• Statement of data retention plan and location
• Status of publications or deposits
• Confirmation that no further participant interaction is planned

Post-approval checklist

• Amendment procedure understood and consent re-approval planned when substantive changes occur
• Continuing review date on the calendar with a 6-week buffer
• Reporting timelines for adverse events and UPIRTSOs documented in the protocol
• Protocol deviation log maintained
• Study team notified of roles in safety monitoring
• Closure memo drafted at the end of the study

Post-approval compliance is where studies most often get into trouble — not at initial review. Build in calendar reminders, assign responsibility to a specific team member, and treat reporting deadlines as non-negotiable. For the foundational pieces that make post-approval easier, revisit the protocol writing guide and the data management guide.