How to search the Cochrane Library

CDSR vs CENTRAL

The Cochrane Library search returns results from several collections, but two matter most:

• CDSR — the Cochrane Database of Systematic Reviews. Full Cochrane reviews and protocols. A few thousand records. This is what you search when you want to know whether a review already exists on your question.
• CENTRAL — the Cochrane Central Register of Controlled Trials. Over 1.9 million records of trials, harvested from MEDLINE, Embase, ClinicalTrials.gov, the WHO ICTRP, and hand-searching. This is what you search when you're collecting trials for your own review.

Reviewers routinely search CDSR when they meant CENTRAL, conclude "there's not much out there," and move on. Check the tab.

Syntax that actually works

• MeSH descriptor: [Dengue] explode all trees — use the MeSH tab to build these; typing them by hand is error-prone.
• dengue:ti,ab,kw — restrict to title, abstract, keywords. This is the workhorse field restriction.
• NEAR/3 — proximity. (fluid NEAR/3 resuscitation):ti,ab,kw catches phrasings that a strict phrase search misses.
• * — truncation. child* covers child, children, childhood.
• Use the Search Manager to build numbered lines (#1, #2, #3) and combine them, exactly as you would in Ovid. Single-box searching does not scale past a trivial question.

Mistakes that silently cost you records

• MeSH-only strategies in CENTRAL. Many CENTRAL records come from trial registries and hand-searching and carry no MeSH at all. Always OR your MeSH terms with free text.
• Forgetting the date limit trap. The default limits in the interface can persist between searches in a session. Confirm them before you record your final numbers.
• Not recording the search date and hit counts. PRISMA requires both. Export the strategy from Search Manager rather than reconstructing it later.
• Treating CENTRAL as trial coverage. CENTRAL is excellent but derives largely from MEDLINE and Embase, so it inherits their language and geographic weighting.

What Cochrane doesn't cover

The Cochrane Handbook itself (§4.3) recommends supplementing with regional databases — LILACS, and national indexes for the regions relevant to your question — precisely because CENTRAL's harvest is skewed toward the major Anglophone indexes. Trials published in Japanese, Portuguese, Spanish, Thai, or Korean journals frequently never enter it.

Searching Cochrane alongside the rest

Symmathy runs one query across Cochrane, PubMed, Europe PMC, ClinicalTrials.gov, J-STAGE, LILACS, DOAJ, HAL, OpenAlex, CrossRef, ThaiJO, and KoreaMed at the same time, deduplicates the overlap, translates non-English titles and abstracts inline, and keeps a record of which sources were queried and how many results each returned for your PRISMA flow diagram.

It doesn't grade, rank, or recommend studies. Screening and appraisal stay with you.