Plan a PubMed Search for a Thesis Literature Review

Turn the question into searchable concepts

PubMed is useful for biomedical and health research, but entering a thesis title rarely produces a complete answer. Separate population, phenomenon and, where relevant, study design. List English synonyms and alternative spellings for each concept. Decide which publication types can answer the question. An initial broad search can reveal vocabulary you did not anticipate.

Example: “Sleep and examination stress among students” may require student, sleep and exam-stress concepts. Start with a known relevant paper and inspect its title words and indexing before fixing the search string. Relying on one everyday phrase will miss articles that describe the same construct differently.

Combine free text with subject headings

PubMed uses search translation and the MeSH controlled vocabulary. MeSH can bring together articles using different terminology, while very recent records may not yet have full indexing. Combining appropriate headings with title or abstract terms can therefore improve coverage. Group synonyms with OR, join concepts with AND and inspect how PubMed interprets the query.

Do not copy a complex search from another review without checking its population, dates and database. Test each concept block, read a sample of relevant and irrelevant results, then refine. Keep successive versions so your eventual hit count can be explained.

Apply filters for a reason

Language, age and publication-type filters make a result set smaller but can exclude useful work. Define eligibility before screening where possible, and justify restrictions. “Free full text” is an access filter, not a quality measure; a university library may provide relevant papers excluded by it.

Screen titles and abstracts using the same criteria. Full text is usually necessary before a final inclusion decision because important design and outcome details may be absent from the abstract. Record reasons for exclusion. If you call the project a systematic review, its reporting and search requirements extend beyond a quick PubMed query.

Write a reproducible methods account

Save the search date, database, exact query, filters and hit count. Export records to a reference manager and inspect their metadata. If you also search PsycINFO, a specialist index or Google Scholar, describe those steps separately. PubMed does not cover every discipline or all grey literature.

Your methods chapter should show how retrieved records became the studies you analysed. Describe limitations honestly rather than retroactively calling a small pragmatic search exhaustive. Finally, compare included papers with the reference list and cite the primary reports for important findings.

Frequently asked questions