PROSPERO Registration Guide: How to Register Your Systematic Review (2026)

What Is PROSPERO and Why Does Your Systematic Review Need It?

PROSPERO was launched in 2011 by the Centre for Reviews and Dissemination (CRD) at the University of York to address a well-documented problem in evidence synthesis: researchers conducting systematic reviews with null or inconclusive results would quietly abandon them, leaving the published literature skewed toward positive findings. By requiring authors to publicly pre-register their research question, methods, and outcomes before they analyse data, PROSPERO creates an auditable record that allows readers, peer reviewers, and future researchers to detect selective outcome reporting.

The practical benefit for authors is equally substantial. A PROSPERO registration number in your manuscript signals methodological rigour to reviewers and editors, reduces the risk of duplication by allowing you to search the database before you begin, and satisfies an explicit submission requirement that has become standard across high-impact clinical journals. In 2026, journals including The Lancet, the BMJ, JAMA Network Open, and Cochrane require or strongly recommend registration before study selection begins, and systematic review authors consistently report that a registration number reduces reviewer queries about methodological transparency.

Who Can Register on PROSPERO? Eligibility Criteria

Not every synthesis study qualifies for PROSPERO registration. The platform is specifically designed for systematic reviews that examine health-related outcomes in human populations. Understanding the eligibility boundaries before you begin will save significant time.

The timing rule is the most frequently misunderstood eligibility requirement: you must submit your PROSPERO registration before you begin extracting data from included studies. You may have already completed your literature search and screened titles and abstracts — that is acceptable. However, if you have opened a single included paper to extract data, you are no longer eligible to register. Journals increasingly cross-check PROSPERO submission timestamps against stated review timelines, and discrepancies can result in rejection or major revision requests on methodological grounds.

How to Register on PROSPERO: Step-by-Step

The PROSPERO registration form contains more than 50 fields, but only a subset are mandatory for initial submission. The following sequence reflects the optimal order of completion, aligned with the PRISMA-P 2015 protocol checklist.

1. Create your PROSPERO account. Navigate to https://www.crd.york.ac.uk/prospero/ and click “Register.” Use an institutional email address where possible. If your institution supports single sign-on, check whether your organisation is listed as a participating partner before creating a standalone account.
2. Click “Register a new systematic review.” You will be directed to a multi-section form. The platform saves drafts automatically, so you do not need to complete the registration in a single session.
3. Enter your review title and background. The title should incorporate the Population, Intervention or Exposure, and study design where possible — for example, “A systematic review of cognitive behavioural therapy for generalised anxiety disorder in adults.” The Background field should briefly state why the review is needed, typically two or three sentences citing the evidence gap.
4. Define your PICO(S) question. The Population, Intervention or Exposure, Comparator, Outcome, and Study design fields are the core of your PROSPERO record. Be specific: vague entries such as “adults with chronic disease” attract reviewer queries. Specify age ranges, diagnostic criteria, intervention dose or form, comparator type, and primary and secondary outcomes with their measurement instruments and timepoints.
5. Paste your search strategy for the primary database. At the time of registration, you must provide at least a draft search strategy for MEDLINE or PubMed. Include the full search string with MeSH terms, Boolean operators, and any limits applied. Indicate all databases you plan to search, such as EMBASE, CENTRAL, PsycINFO, and CINAHL.
6. Specify your inclusion and exclusion criteria. Use parallel structure: state what you will include first — study design, population, comparator, language, publication date range — then what you will exclude. Reviewers flag entries where inclusion and exclusion criteria overlap or contradict each other.
7. Describe your data extraction and risk of bias methods. Identify the extraction instrument, the risk of bias tool appropriate to your study design — Cochrane RoB 2 for RCTs, ROBINS-I for non-randomised studies, Newcastle-Ottawa Scale for cohort or case-control designs — and how discrepancies between reviewers will be resolved.
8. Add your review team. List all team members with their affiliations, ORCID identifiers (strongly recommended in 2026), and roles. The corresponding author’s email is publicly visible in the published record — use an address you monitor regularly, as contact queries from other researchers are common.
9. State your data synthesis plan. If you plan a meta-analysis, specify the effect measure (odds ratio, risk ratio, mean difference, standardised mean difference) and the statistical model (fixed-effect or random-effects). Pre-specify any planned subgroup analyses. If quantitative synthesis is not planned, state the narrative synthesis approach you will follow.
10. Declare conflicts of interest and submit. The funding source and conflicts of interest fields are mandatory. PROSPERO assigns a CRD number immediately upon submission of a complete record. The record typically takes 3–7 working days to appear publicly while CRD completes quality screening, but your CRD number is valid and citable from the moment of submission.

Key Information to Include in Your PROSPERO Submission

The quality of a PROSPERO record is judged by its completeness and specificity. A record that describes outcomes as “clinical outcomes” or search strategy as “major databases” will be queried by CRD staff, delaying public visibility of the record. The following fields receive the most reviewer attention and warrant careful completion.

Outcomes: Specify each primary and secondary outcome with the measurement instrument, scale or unit, and planned follow-up timepoint. For example: “Primary outcome: depressive symptoms measured by the Hamilton Depression Rating Scale (HAM-D) at 12 weeks.” Journals can and do check whether the primary outcome in the published review matches the primary outcome registered on PROSPERO — discrepancies are a recognised form of outcome reporting bias.

Search strategy: Paste the full MEDLINE search string at the time of registration. If you plan to run a more comprehensive search after registration, indicate this, but you must provide at least a preliminary search string so reviewers can assess its scope.

Anticipated completion dates: Estimate review start and end dates. These are not legally binding, but a review published years after its stated completion date may attract methodological queries about interim data access.

ORCID integration: Since 2023, PROSPERO has supported ORCID link-through for the corresponding author, and by 2026 this has become standard practice. Linking your ORCID at account creation establishes persistent cross-platform researcher identity that connects your PROSPERO record to your publication portfolio.

Pre-Registration Checklist

Common Mistakes That Delay or Invalidate PROSPERO Registrations

CRD staff perform quality checks on submitted records before making them publicly visible. The following errors are the most common causes of delayed publication or reviewer queries from the CRD team.

Registering after data extraction has begun. This is the most consequential error because it makes the record ineligible, not merely delayed. If you have already opened included studies to extract data, do not submit to PROSPERO — the timestamp mismatch will be visible when your manuscript enters peer review. Some researchers attempt to register a new protocol for an updated version of a review; consult CRD guidance before attempting this approach.

Vague outcome specification. “Clinical improvement” or “patient outcomes” will be queried every time. Each outcome requires a named measurement instrument, the scoring direction, and a follow-up timepoint.

Inconsistency between PICO fields. The Population field states “adults aged 18–65” but the Exclusion criteria state “no upper age limit.” Reviewers flag every internal contradiction between fields.

Failing to update the record after protocol amendments. When your methods change — a new database is added, an outcome is dropped, or an eligibility criterion is refined — update the PROSPERO record promptly and document the reason. PROSPERO maintains a version history, and unexplained deviations between the registered protocol and the published review are a recognised peer-review red flag.

Leaving the search strategy as a placeholder. “Search strategy to be added” is not acceptable at submission. Paste the actual MEDLINE string, even if you plan to run a more comprehensive search after registration.

How to Update Your PROSPERO Record After Submission

PROSPERO supports protocol amendments and maintains a full, publicly visible version history of all changes. You can update your record at any stage of the review — each amendment is date-stamped and visible, which is the mechanism by which transparency is enforced. The process is: log in to your PROSPERO account, navigate to your registered review, select “Amend record,” modify the relevant fields, provide a brief explanation for each change, and resubmit.

Update your record when you add new databases to your search, change the risk of bias tool, revise outcome definitions, add or remove team members, update anticipated completion dates, or flag that the review has been submitted for publication. Many authors also update the PROSPERO record to add the DOI of the published review once accepted, creating a permanent link between the registration and the final publication in both databases.

PROSPERO and PRISMA-P: How They Work Together

Registering on PROSPERO and reporting your protocol using the PRISMA-P 2015 checklist are complementary but distinct steps. PROSPERO is a registry — a searchable database of pre-registered protocols that assigns a CRD number and establishes a public time-stamp. PRISMA-P (Preferred Reporting Items for Systematic review and Meta-Analysis Protocols) is a 17-item reporting guideline developed by Shamseer and colleagues for how to write and publish a standalone protocol article in a journal such as Systematic Reviews or BMJ Open before the full review is completed.

In practice: you register on PROSPERO to obtain a CRD number — fast, free, and immediately citable. You then optionally write a full protocol article using PRISMA-P 2015, citing your PROSPERO number in that article. The published protocol serves as a detailed methods reference that reviewers and readers can consult when your full systematic review is eventually published. For researchers conducting PRISMA-compliant systematic reviews, the PROSPERO registration number belongs in the Methods section of the manuscript, typically in the first paragraph of the Search Strategy or Protocol subsection.

PROSPERO Registration and Journal Requirements in 2026

The proportion of journals requiring PROSPERO registration has grown substantially since 2022. As of 2026, a prospective PROSPERO record is required for systematic review submissions at Cochrane, the BMJ, The Lancet, JAMA Internal Medicine, Annals of Internal Medicine, and most specialist systematic review journals. A further group of journals, including many JAMA network titles and high-impact specialty journals, strongly recommend registration and may return manuscripts without a CRD number to authors for registration before peer review begins.

Peer reviewers are increasingly checking three specific details when they encounter a PROSPERO number: whether the registration date precedes the stated data extraction start date; whether the primary outcome in the manuscript matches the primary outcome registered on PROSPERO; and whether any protocol amendments are documented in the registration record. Manuscripts that deviate from their registered protocol without a versioned PROSPERO amendment face a substantially elevated risk of major revision or rejection on methodological grounds alone.

How Editverse Supports Your Systematic Review from Protocol to Publication

The PROSPERO registration is the starting point of a systematic review. From database searching and title and abstract screening to meta-analysis, PRISMA flow diagram preparation, and full manuscript writing, each stage carries specific methodological and reporting requirements. Editverse’s PRISMA-compliant systematic review writing service supports researchers at every stage — whether you need guidance completing your PROSPERO record, constructing a comprehensive database search strategy, or preparing a submission-ready manuscript with all required reporting elements for your target journal.

Our team includes experienced systematic reviewers who have supported reviews published in The Lancet, JAMA, and Cochrane, and who understand the methodological expectations that high-impact journals apply to registered reviews. If you are uncertain about any aspect of your PROSPERO submission — eligibility, PICO formulation, search strategy scope, or registration timing — contact our manuscript writing team for a protocol review before you register.

References

1. Centre for Reviews and Dissemination. PROSPERO: International prospective register of systematic reviews. University of York; 2011–2026. Available at: https://www.crd.york.ac.uk/prospero/
2. Shamseer L, Moher D, Clarke M, et al. Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: elaboration and explanation. BMJ. 2015;349:g7647. doi:10.1136/bmj.g7647 (PMID: 25554246)
3. Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ. 2021;372:n71. doi:10.1136/bmj.n71 (PMID: 33782057)

Editverse Research Team | Updated June 2026