Methodology & Verification
How we build and verify the evidence
Vagus Research catalogues 837 human vagus nerve stimulation studies. Every record is drawn from real, indexed, peer-reviewed literature — never invented. We are transparent about which summaries a human has verified and which are machine-extracted.
Verification tiers
Each study page shows how its plain-language summary was produced:
- ✓ Verified summary — a human has checked the condition classification and key finding against the study's abstract.
- Auto-extracted · verification pending — the summary was drafted from the abstract (by extraction or AI assistance) and is awaiting human verification. It is checkable against the cited source.
What we exclude from the study count
Study protocols (registered trials with no results yet), editorials, letters, and other commentary are tagged and kept for context but not counted as studies. Registered protocols appear separately as “results pending”. Retracted publications are removed entirely — they never appear in the database or its downloadable, citable dataset.
Classification standards
Condition is derived from the paper's indexed subject headings, not from the search that surfaced it. Study type and evidence tier follow the publication's catalogued type (a review is never listed as a randomised trial). Participant counts are taken from the source or omitted — never guessed. A study that genuinely spans two conditions appears on both.
Open data
The full dataset (1,340 records, including preclinical) is released under CC BY 4.0 and archived with a permanent DOI. See the Evidence Database to download it.