PRESS Checklist: Getting Your Search Strategy Peer-Reviewed

Every study your review finds depends on your search strategy being right — and errors here are invisible until someone who didn't write the search actually checks it. PRESS (Peer Review of Electronic Search Strategies) is the standard framework for that check.

Why search strategies need independent review

The person who builds a search strategy is the worst-positioned person to catch their own errors in it — missed synonyms, an overly narrow filter, or a Boolean logic mistake all feel invisible to the person who wrote them. A second, independent reviewer (ideally an information specialist or librarian) catching these before screening begins is far cheaper than discovering a search flaw after you've already screened thousands of records.

The PRESS domains

• Translation of the research question — does the search actually capture the PICO elements of your question?
• Boolean and proximity operators — correct use of AND/OR/NOT and proximity searching, and common logic errors (e.g., a misplaced OR that narrows results instead of broadening them).
• Subject headings — appropriate use of controlled vocabulary (e.g., MeSH terms in PubMed, Emtree in Embase), not just free-text keywords.
• Text word searching — sufficient synonyms, spelling variants, and truncation to catch how a concept is actually described in the literature.
• Spelling, syntax, and line numbers — technical errors that can silently break a search without triggering an obvious error message.
• Limits and filters — date, language, or publication-type restrictions applied appropriately and justified, not just carried over from habit.

What a PRESS review actually catches

Common findings include missing synonyms for a key concept, subject headings applied inconsistently across databases (each database has its own controlled vocabulary and needs its own translation, not a copy-pasted string), and filters that unintentionally exclude eligible study types.

When to get your search reviewed

Before screening begins — ideally during protocol development, since revising a search strategy after screening has started means redoing that work. Many journals and some PROSPERO reviewers now explicitly ask whether a librarian or information specialist reviewed the search strategy.