Cochrane Library

Cochrane Library

Cochrane systematic reviews are the gold standard for evidence-based medicine. Accessed via PubMed E-utilities searching the "Cochrane Database of Systematic Reviews" journal. Use journal filter: cochrane+database+syst+rev[journal]. E-utilities endpoints: esearch.fcgi (search), efetch.fcgi (retrieve records), esummary.fcgi (document summaries). Returns PMIDs which can be fetched for full citation data. Free, no auth needed for moderate usage (<3 req/sec).

Data Model

• Search results — PubMed IDs (PMIDs), result count, translation of query terms.
• Document summaries — title, authors, journal, publication date, DOI, abstract.
• Full records — retrieve complete article details by PubMed ID: full abstract text, author affiliations, MeSH terms, and DOI. Structured MEDLINE/PubMed XML from efetch is parsed into readable fields (not only search summaries).
• Journal filter — cochrane+database+syst+rev[journal] restricts to Cochrane reviews only.

Gotchas

• Rate limits: 3 requests/second by default; configured NCBI credentials raise the cap to 10 req/sec.
• Two-step retrieval: esearch returns PMIDs, then efetch/esummary retrieves the actual records.
• retmode parameter: use retmode=json for JSON output from esearch/esummary. efetch returns XML only.
• URL encoding: spaces in search terms should be encoded as + in the term parameter.
• Journal name: the exact journal filter is cochrane+database+syst+rev[journal] (abbreviated title).