PubMed, MEDLINE and PMC: check the record before describing the journal

1. Give each resource its proper role

NLM describes PubMed as a free resource containing citations and abstracts, with links to full text elsewhere. MEDLINE is its largest component and uses Medical Subject Headings, or MeSH, for indexing. PMC is a full-text archive. These definitions concern different functions; they are not interchangeable badges for a publisher’s website.

PMC also includes author manuscripts and preprints within its stated collections. Read the version label on the actual item. A free full-text link, a PubMed identifier and a statement about peer review answer different questions. The presence of one should not be used to invent the others or to replace reading the record and article.

Reference: NLM: About PubMed · NLM: About MEDLINE · NLM: About PMC

2. Resolve article identity before status

Begin with the title, author names, year, journal and any identifier actually supplied by the primary record. Check that the identifier resolves to the same work. A similar title, a conference abstract and a later full report can describe related research while remaining separate publications. Preserve the version you intended to verify.

Record the source address and access date alongside the fields used for the match. If the citation is incomplete, leave the match unresolved and request the missing detail. Do not borrow a PMID from a similarly named article. If the supplied identifier points elsewhere, retain that discrepancy rather than replacing it silently and calling the original citation verified.

3. Make the article-level check reproducible

The PubMed User Guide documents medline[sb] as the MEDLINE subset filter. After confirming an actual PMID, search that identifier and then combine it with the filter, preserving the query and date. This is a bounded record check. Use the real identifier you verified; the lettered examples below are teaching labels and cannot be executed as PMIDs.

If the filter does not return the article, report that result at the time checked. It does not establish why the record is outside that subset, whether it will later be indexed, or whether the journal fails a quality standard. A broken connection or failed query is a failed check, not evidence that the article is absent.

Reference: NLM: PubMed User Guide

4. Compare three fictional evidence packets

Suppose an editor checks three invented packets on 15 September 2026. Packet A contains a correctly matched PubMed record and a saved query showing that same record in the MEDLINE subset. Packet B contains a correctly matched PubMed record and a PMC author-manuscript page; its saved MEDLINE-subset query returns no match. Packet C contains only a publisher’s unsourced statement about visibility.

These supplied facts justify different conclusions. A supports article-level MEDLINE evidence at that date. B supports PubMed discovery and the specified archived version, but not MEDLINE-subset membership. C needs an independent record check. None of these packets includes current journal-level coverage evidence, so none establishes that separate claim.

On small screens, scroll the table horizontally, or focus it and use the arrow keys.

5. Open a separate journal evidence record

The PubMed guide directs readers to the NLM Catalog for journal information. Match the journal title and its history carefully; an abbreviation or title change can lead to the wrong serial. Record the catalog entry, relevant indexing information and any stated coverage period. Keep the exact wording and date instead of reducing the record to a permanent yes-or-no badge.

Then compare the article’s publication date and journal identity with that evidence. If the relevant period is unclear, the coverage conclusion remains unresolved. A journal-level statement does not automatically verify every article, and an individual archived manuscript does not document the journal’s participation route. Those questions may require different NLM records or clarification.

Reference: NLM: PubMed User Guide · NLM Catalog Help: journal identity and indexing fields

6. Publish only the conclusion the check supports

For fictional B, a careful internal note says that the matched article was found in PubMed, that the linked PMC version is an author manuscript, and that the checked MEDLINE-subset query did not return it. Add that journal coverage has not been established. Keep the query receipt with the assessment; a marketing sentence should never strengthen it into a broader indexing claim.

Refresh checks when preparing a public statement or when a journal record changes. Save earlier evidence as a dated snapshot rather than overwriting its meaning. The maintained NLM pages linked here should be preferred to copied older comparison sheets. Verification is complete only for the identity, resource, version and date actually examined.

Questions for a practical final check

• Article identity and version matched.
• PMID taken from the real record.
• Query, date and result retained.
• A failed request not counted as absence.
• Journal coverage checked separately.
• Public wording does not exceed the evidence.