Systematic Review Registries Beyond PROSPERO

PROSPERO is the best-known systematic review registry, but it doesn't accept every review type, and researchers working on scoping reviews, non-health topics, or certain other review methodologies need to know the legitimate alternatives rather than assuming PROSPERO is the only option or, worse, skipping registration entirely when PROSPERO doesn't fit.

Why PROSPERO has limits

PROSPERO specifically registers systematic reviews with a health-related outcome. It does not accept protocols for reviews already completed, and it does not accept scoping review protocols at all, given how differently scoping methodology is structured compared to a standard systematic review. Researchers working outside these boundaries need a different registry, not an assumption that registration simply isn't available or required for their review type.

The Open Science Framework as the most flexible alternative

OSF Registries accepts protocols for a much broader range of research, including scoping reviews, reviews outside health-related fields, and other review types PROSPERO doesn't cover. It doesn't have PROSPERO's specific health-focused review structure, meaning the registration form is more general-purpose, but this flexibility is exactly what makes it suitable for review types PROSPERO wasn't built for.

INPLASY as a growing PROSPERO alternative

The International Platform of Registered Systematic Review and Meta-Analysis Protocols, INPLASY, has emerged as another option, particularly for reviews that might not clear PROSPERO's specific inclusion requirements or during periods of high PROSPERO submission volume when processing times lengthen. It follows a broadly similar registration structure to PROSPERO, making the transition between the two relatively straightforward for researchers already familiar with PROSPERO's format.

Cochrane's own registration pathway

Reviews intended specifically for the Cochrane Database of Systematic Reviews follow Cochrane's own internal registration and title approval process, which serves a similar pre-specification function to PROSPERO but operates through Cochrane's own editorial system rather than an external registry.

Registries for non-health systematic reviews

Fields like education, environmental science, and criminology increasingly expect systematic review registration as good practice, and OSF Registries, alongside some field-specific registries such as the Campbell Collaboration's own protocol system for social science and policy reviews, provide appropriate registration pathways for these non-health topics where PROSPERO simply doesn't apply.

Choosing the right registry for your specific review

If your review has a health-related outcome and follows standard systematic review methodology, PROSPERO remains the most widely recognized and expected choice. If you're conducting a scoping review, OSF Registries is generally the appropriate choice regardless of topic area. If your review sits outside health entirely, checking whether your specific field has a dedicated registry, and defaulting to OSF Registries if not, is a reasonable approach.

What matters more than which specific registry you use

The core purpose of registration -- creating a public, timestamped record of your planned methodology before you see your results -- applies regardless of which specific registry you use. A review registered on OSF with a clear, complete, pre-specified protocol is more credible than one registered on PROSPERO with vague, underspecified fields, and the choice of registry matters less than the genuine completeness and honesty of what you actually register.

Citing your registration correctly in your manuscript

Whichever registry you use, cite it explicitly in your abstract and methods section, including the registration number and a direct link where possible, exactly as you would for a PROSPERO registration. Reviewers and readers unfamiliar with a less common registry may need this direct link to verify your registration exists and matches your reported methods, making this citation detail more important, not less, when using a less universally recognized registry.

Registering when no clearly appropriate registry exists

In the rare case where your specific review type and topic area genuinely have no clearly fitting registry available, documenting your protocol with a clear date stamp through another mechanism -- a preprint of your protocol, a dated institutional repository submission -- and stating this approach transparently in your manuscript is a reasonable fallback, though genuinely rare given how broad OSF Registries' scope already is across most review types and fields.

Transferring a registration between registries

It's occasionally necessary to move a protocol between registries mid-project, for instance if a review's scope shifts from a health-specific question toward one that no longer fits PROSPERO's requirements. When this happens, registering on the more appropriate alternative registry and explicitly noting the transition, including both registration numbers, in your final manuscript maintains transparency rather than leaving readers to wonder why your citation references an unfamiliar registry without context.

Registry choice and journal expectations

Some journals and editors are more familiar with PROSPERO specifically and may ask about an unfamiliar registry during peer review. Being prepared to briefly explain, in your cover letter or response to reviewers, why a different registry was the more methodologically appropriate choice for your specific review type helps address this kind of question before it becomes a point of friction during the review process. Most reviewers, once given a brief, clear explanation, accept a well-justified alternative registry choice without further objection, provided the underlying registration itself is genuinely complete and appropriately timed. This kind of brief, prepared explanation costs little to have ready and can prevent an otherwise straightforward registry choice from becoming an unnecessary sticking point during an already demanding revision process. Having this explanation ready in advance, rather than composing it hastily in response to an unexpected reviewer question, generally results in a clearer, more persuasive justification for your registry choice. This small amount of preparation reflects the same general principle that applies throughout a systematic review: anticipating a reasonable question before it's asked is almost always more effective than responding to it only after the fact. This same discipline of anticipating reasonable questions in advance, applied consistently, tends to make an entire submission and review process considerably smoother from start to finish, benefiting both the review team and everyone who eventually relies on the resulting published work, closing the loop on a small decision that started at the very earliest planning stage of the entire project, long before the final manuscript was ever drafted.