PROSPERO Registration: When and How to Register

PROSPERO (International Prospective Register of Systematic Reviews) is the public registry for systematic review protocols. Register before you begin data extraction. PROSPERO does not accept a systematic review if data extraction has already started (Eligibility). To complete the form, describe your question (PICO/PEO), eligibility criteria, search methods, selection and data-extraction process, risk-of-bias approach, and synthesis plan in clear, specific terms. Registering early creates a time-stamped record that reduces bias and prevents duplicate effort.

If you need a quick refresher on terms, see the glossary of SLR terminology. New to the workflow? Start with the quick-start guide. If you are still drafting your protocol, the SRT protocol development tool can help you structure the core sections you will enter into PROSPERO.

PROSPERO registration steps

Steps below were checked against the PROSPERO site, Oct 2026.

1. Sign up and log in. A member of the review team completes the online registration. They must have signed up for a PROSPERO account and be logged in. There is no charge to register or to search. (How to register; About PROSPERO)

2. Register before data extraction starts. PROSPERO does not accept systematic reviews that have already started data extraction, or individual-participant-data reviews that have already obtained some datasets. (Eligibility)

   Scoping reviews are not currently accepted (Eligibility). The live register should not be used for reviews produced during student modules or other training projects. Use the student project option instead: those records can be stored and shared with supervisors, but they are not published and are not found in PROSPERO searches (How to register).

3. Enter the design, methods, team, funder, and timelines. The form asks for key information about the review design and methods, and about the review team, funder, and timelines. A PROSPERO record is not a full protocol. A PDF of the full protocol may be uploaded with the record. (How to register)

4. Respond if similar reviews are found. PROSPERO uses what you enter to look for similar reviews already registered. If it finds any and you continue, you are asked why the new review is needed. Giving a reason is not mandatory. The reason you provide, including none, is stored in the record. (How to register)

5. Complete the automatic checks. The system checks data as they are entered and may ask for more information. (How to register)

6. Get guarantor approval and team confirmation. When data entry is complete, a named guarantor (usually the senior member of the review team) must approve the record. Every named team member must confirm participation and consent to their name and email being published. (How to register)

7. Receive the registration number. Once those confirmations are complete, a registration number is assigned and the record is published immediately. There is no delay to publication. (How to register)

Why PROSPERO Registration Matters

Guarding Against Reporting Bias

One of PROSPERO's primary functions is to create a public, time-stamped record of your planned methods before you begin data extraction. This prospective registration helps prevent:

• Selective outcome reporting - When researchers only report findings that support their hypotheses
• Post-hoc outcome switching - Changing planned outcomes based on what the data shows
• HARKing (Hypothesizing After Results are Known) - Presenting exploratory findings as if they were planned from the start

By registering your protocol early, you establish a clear record of your intended methods, making any deviations transparent and accountable.

Preventing Unnecessary Duplication

Research waste is a significant problem in academia. PROSPERO helps address this by:

• Making ongoing work visible to other research teams
• Allowing stakeholders to track relevant reviews in their field
• Supporting efficient use of research funding by avoiding redundant efforts
• Enabling collaboration between teams working on similar topics

Meeting Modern Research Standards

Registration is increasingly expected by:

• Funding bodies who want to ensure research efficiency
• Academic journals that require protocol registration for publication
• Professional organizations promoting research transparency
• Systematic review guidelines like PRISMA and Cochrane standards

What You Need Before Registration

A PROSPERO record is not considered a full protocol. Before you register, be ready to describe the review design and methods, and the review team, funder, and timelines. You may upload a PDF of the full protocol with the record (How to register).

Core Protocol Elements

Review Question and Background

• Clear, focused question using PICO/PEO framework
• Comprehensive background justifying the review's importance
• Specific objectives and scope

Eligibility Criteria

• Population: Who will be included (age, condition, setting)
• Intervention/Exposure: What treatments or exposures you're studying
• Comparator: What comparison groups you'll use
• Outcomes: Primary and secondary measures
• Study Designs: Types of research you'll include
• Settings: Geographic or institutional boundaries

Search Strategy

• Databases you'll search (PubMed, Cochrane, Web of Science, etc.)
• Date limits and language restrictions
• Grey literature sources
• Supplementary search methods (reference checking, expert consultation)

Outcomes and Analysis Plan

• Primary and secondary outcomes with clear definitions
• Planned subgroup analyses or sensitivity analyses
• Statistical methods for meta-analysis (if applicable)
• Risk of bias assessment tools
• Data synthesis approach (narrative, quantitative, or mixed methods)

What the current form asks for

The February 2025 PROSPERO form is organised in sections, not a fixed count of 22 mandatory fields. That older core-dataset summary is out of date. On a published record the sections include review title and basic details, eligibility, timeline, searching and screening, data collection (including risk of bias), outcomes, planned synthesis, current review stage, publication of results, the review team, and funding. Full search strings can be a link or an attachment. Do not paste a very long string into a short box.

Not eligible

Use the OSF Generalized Systematic Review worksheet when PROSPERO will not accept the review:

• Data extraction has already started, or individual participant datasets have already been obtained
• The review is a scoping review, an evidence or gap map, or a literature review
• The review is a systematic critical appraisal or a review of clinical practice guidelines
• The outcome is indirect (for example educational attainment or sporting performance)
• The results will not be made public

Reviews produced during student modules or other training projects stay on PROSPERO's student project option. Those records can be stored and shared with supervisors, but they are not published and are not found in PROSPERO searches (How to register).

Cochrane protocols are already registered. Do not create a second PROSPERO record. A review of human and animal studies needs two PROSPERO records, cross-referenced. Animal-only reviews should open the animal form and switch to OSF if PROSPERO rejects it.

Managing Your Protocol After Registration

Handling Protocol Changes

Research protocols sometimes need adjustment based on real-world considerations. If you must deviate from your registered plan:

• Document all changes with clear justifications
• Update your PROSPERO record to maintain transparency
• Report deviations in your final publication
• Consider amendments for major changes (PROSPERO allows updates)

Linking to Final Publications

When you complete your review:

• Cite your PROSPERO registration in the published manuscript
• Report the registration in the abstract and in PRISMA 2020 item 24a (PRISMA 2020 checklist)
• Reference the protocol in your methods section
• Update the registration record when the review is completed, and include citation details (How to register)

Common Challenges and Solutions

Challenge: Getting Started

Solution: Use PROSPERO's online guidance. Many institutions provide protocol development support. The SRT protocol development tool can also help you structure the fields PROSPERO requires.

Challenge: Keeping Within Word Limits

Solution: Focus on essential details. Use appendices for complex search strings or detailed analysis plans.

Challenge: Timing Your Registration

Solution: Register as early as possible but ensure your protocol is sufficiently developed. Remember: PROSPERO rejects records if data extraction has already started (Eligibility).

Challenge: Managing Team Contributions

Solution: Clearly define roles in the registration and ensure all team members review the final submission.

The Future of Protocol Registration

As research transparency becomes increasingly important, protocol registration is likely to become mandatory for more journals and funders. The current version of PROSPERO was launched in February 2025 (About PROSPERO).

By registering your systematic review protocol with PROSPERO, you're not just following best practices—you're contributing to a more transparent, efficient, and credible research ecosystem. The time investment in proper registration pays dividends throughout your review process and beyond.

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Resources:

• PROSPERO website: crd.york.ac.uk/prospero
• PRISMA-P guidelines for protocol reporting
• Cochrane Handbook: Chapter on protocol development