Is PROSPERO registration free?

Yes. PROSPERO is free to use. You need an account and should allow time for registration checks before your CRD number is published.

Can I register after I have already started screening?

PROSPERO allows retrospective registration but marks the record accordingly. Many journals prefer prospective registration. Register as early as possible — ideally before screening.

What is the difference between PROSPERO and a clinical trial registry?

Clinical trial registries (e.g. ISRCTN, ClinicalTrials.gov) register individual trials. PROSPERO registers systematic review protocols that synthesise evidence across multiple studies.

Do I cite PROSPERO in my dissertation?

Yes. Include the PROSPERO ID (CRD420xxxxxx) in the abstract, methods, and appendix. Link to the public record so examiners can verify your pre-specified methods.

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How to Register a Systematic Review on PROSPERO (Step-by-Step)

When registration is required, what to include in each field, amendments, and how PROSPERO links to PRISMA and journal submission

Quick answer

PROSPERO is the international prospective register for systematic reviews. Register before screening begins when possible. Your record needs a clear PICO, inclusion criteria, search sources, outcomes, and analysis plan — matching what you will report in PRISMA 2020.

1. When PROSPERO registration is expected

PROSPERO accepts registrations for systematic reviews with clearly defined eligibility criteria addressing health or social care questions. Most UK medical school dissertation supervisors and specialty journals expect prospective registration before formal screening.

Registration reduces duplication (other teams may already be reviewing your question), supports transparency (readers can compare protocol to published methods), and is a PRISMA 2020 reporting item.

Scoping reviews, rapid reviews without full systematic methods, and reviews of non-health topics may use other registries or institutional protocol repositories. Check PROSPERO eligibility criteria before starting.

Systematic review of interventions, diagnostics, prognostic factors, or qualitative synthesis (with appropriate methods)
Not eligible: bibliometric analyses, single-study reviews, or reviews without defined inclusion criteria
Register before title/abstract screening when feasible
Retrospective registration is permitted but flagged — editors may scrutinise post-hoc changes

2. Key PROSPERO fields (what reviewers expect)

Review title should state the population, intervention or exposure, comparator if any, and outcomes — not a vague topic label.

Review question: write a structured PICO or PEO. Reviewers and supervisors should be able to derive screening criteria directly from this section.

Condition or domain: map to PROSPERO categories for discoverability.

Participants: inclusion and exclusion criteria with age, setting, diagnosis definitions.

Intervention / exposure and comparator: define clearly for non-pharmacological interventions (dose, duration, delivery).

Outcomes: separate primary and secondary outcomes with time points. Pre-specify if you will use GRADE.

Study design: which designs will be included (RCT, cohort, etc.) and which excluded.

3. Search strategy and sources

PROSPERO asks which databases and supplementary sources you will search. Listing only PubMed is rarely sufficient for publication-grade reviews. Cochrane guidance expects MEDLINE, Embase, CENTRAL, and trial registries where relevant, plus reference checking and citation searching.

You may register before the final search string is perfected, but the strategy section should describe concepts (population, intervention, comparator) and planned limits (language, date). Update the record when the final strategy is run.

Document planned grey literature sources (thesis repositories, regulatory documents) if applicable to your question.

4. Synthesis and analysis plan

State whether you plan narrative synthesis only, meta-analysis, network meta-analysis, or subgroup analyses. Pre-specify effect measures (RR, OR, MD, SMD, HR) and models (random vs fixed effects) with rationale.

Describe how heterogeneity will be assessed (I², prediction intervals) and what will trigger subgroup or sensitivity analyses.

If meta-analysis is inappropriate, explain why (expected heterogeneity, diverse outcomes) — this prevents post-hoc claims that pooling was 'always planned'.

5. Amendments and protocol deviations

Amend PROSPERO when inclusion criteria, outcomes, or analysis plans change materially. Minor clarifications may not require amendment but should be documented in the final manuscript.

In the published review, include a 'differences from protocol' subsection or table comparing registered and final methods. Unexplained deviations (especially outcome switching) trigger selective reporting concerns.

Journal editors compare PROSPERO to submitted manuscripts — align your PRISMA flow, outcomes, and RoB tools with the registered protocol.

6. Practical timeline for students

Week 1–2: Draft PICO, scoping search, supervisor agreement on question feasibility.

Week 2–3: Complete PROSPERO registration; obtain CRD number.

Week 3+: Run full search, import to screening tool, begin dual screening.

Allow 5–10 working days for PROSPERO editorial checks on first submission — do not leave registration to the day before your dissertation deadline.

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