How to Develop a Reproducible Literature Search Strategy

A reproducible search strategy is one that another researcher could run and obtain the same records: the databases, platforms, exact search strings, dates, limits and any additional methods are all recorded. Reproducibility is a requirement for systematic reviews and good practice for any review.

Steps

1. Define the question (PICO or equivalent) and eligibility criteria.
2. Build a concept grid with controlled vocabulary and free-text terms for each concept.
3. Choose sources: several databases (for example MEDLINE/PubMed, Embase, Cochrane CENTRAL), trial registries and grey literature as appropriate.
4. Write the strategy for one database, then translate it to the others, adapting field tags and vocabulary.
5. Validate: check that known relevant papers are found.
6. Peer-review the search with an information specialist or librarian where possible.
7. Run and record the search with date, platform and counts.
8. Update before publication if the search is old.
9. Report using PRISMA-S.

What to record

MRN's free search strategy template provides a log and concept grid.

Illustrative example

Invented for teaching. A team documents that the PubMed search was run on 1 March 2026, retrieved 1,204 records, and that the same search in Embase retrieved 1,630. After removing duplicates, 2,100 records were screened. A second team member can repeat each search from the log.

Peer review of the search and updates

Ask an information specialist or librarian to review the strategy before you run it; errors in syntax and missing terms are common and easy for another person to spot. Plan an update search shortly before submission, because databases add records daily and a search more than a year or so old may be considered out of date by reviewers and editors. Keep each version of the strategy with a date.

Common pitfalls

• Copying a search from a paper without adapting syntax.
• Not saving the date and platform.
• Using only one database for a systematic review.

Key takeaways

• Document everything needed to rerun the search.
• Validate with known studies and have the search peer reviewed.

This page is general educational information about research methods. It is not medical, legal or regulatory advice; follow your institution's ethics board and your target journal's instructions.