Direct comparison
Single IRB vs. Local IRB Review
Single IRB (sIRB) vs. local IRB review for multi-site research: when each applies, the regulatory basis, and what stays local under an sIRB.
Side-by-side comparison
| Dimension | Single IRB (sIRB) Review | Local IRB Review |
|---|---|---|
| What it means | One IRB of record reviews the protocol on behalf of every participating site. | Each site's own IRB independently reviews and approves the protocol for its own site. |
| Regulatory basis | 45 CFR 46.114(b) (Common Rule cooperative-research provision, compliance date Jan. 20, 2020); NIH sIRB policy (effective Jan. 25, 2018) for NIH-funded studies. | Baseline Common Rule requirement that research be reviewed by an IRB (45 CFR 46.109) — the default absent an sIRB arrangement. |
| When it applies | Non-exempt, protocol-identical, multi-site (cooperative) human subjects research at U.S. domestic sites, funded/supported by a Common Rule agency, unless a documented exception applies. | Single-site studies; multi-site studies with a documented sIRB exception; exempt research; research outside Common Rule/NIH sIRB scope. |
| Who conducts the review | One IRB — a lead institution's own IRB acting centrally, a commercial/independent IRB, or a reliance-network arrangement (e.g., SMART IRB). | Each participating site's own institutional IRB, separately. |
| Documentation mechanism | IRB Authorization Agreement (IAA) / reliance agreement between the IRB of record's institution and each relying site. | No reliance agreement needed — each site holds its own approval under its own Federalwide Assurance (FWA). |
| What stays with the local site | Local context review, consent-document customization, local investigator/staff qualifications, and local reportable-event/noncompliance handling. | Everything — the local IRB's review and approval covers all of it directly. |
| Continuing review & amendments | Handled once, at the IRB of record, on behalf of all relying sites. | Each site processes its own continuing review and amendments independently. |
| Effect on multi-site startup | Removes duplicative substantive review at every site and tends to produce more consistent protocol interpretation across sites. | Each site's IRB may request different changes, which can slow coordinated startup across a large multi-site study. |
| Typical exceptions | Funding agency determines sIRB isn't appropriate for the study; non-U.S. sites; research outside the cooperative-research provision's scope. | N/A — this is the default absent an sIRB arrangement. |
| Where it's most common | NCI/NIH cooperative group trials, multi-site clinical trials, consortium studies funded by Common Rule agencies. | Single-site studies, small pilot studies, and studies where local law or institutional policy requires local review. |
Common questions
FAQ
Does sIRB review eliminate the need for local IRB involvement entirely?+
No. Even when a single IRB of record reviews the protocol, the relying site typically still handles local context review, consent-form customization, local investigator qualifications, and local reportable-event reporting through its own research-compliance office.
Is single IRB review mandatory for every multi-site study?+
It's the expected default for non-exempt, protocol-identical, multi-site human subjects research funded or supported by a federal agency that has adopted the Common Rule (45 CFR 46.114(b)), or for NIH-funded studies under NIH's separate sIRB policy — but a federal funding agency can document that sIRB isn't appropriate for a specific study, and exempt research and non-U.S. sites fall outside the requirement.
What is an IRB Authorization Agreement (IAA)?+
An IAA is the written agreement between the IRB of record's institution and a relying site under which the relying site's IRB formally cedes review authority for a specific study, while spelling out which responsibilities (local context review, reportable events, consent customization) remain with the relying site. SMART IRB is a widely used master reliance agreement that many U.S. institutions have already signed, which speeds up executing individual study-level reliance.
How is the NIH sIRB policy different from the Common Rule's sIRB requirement?+
The NIH policy (effective January 25, 2018) applies specifically to NIH-funded, non-exempt, multi-site human subjects research. The Common Rule's cooperative-research provision at 45 CFR 46.114(b) (compliance date January 20, 2020) is broader: it applies to U.S. domestic sites in cooperative research conducted or supported by any Common Rule federal department or agency, not NIH funding alone.
