Research Library Guide
How to read, search, and trust the ASH research library — and what its size does and does not mean.
The ASH research library is a bibliographic index of the published literature relevant to medicinal leech biology, hirudotherapy, and leech-derived compounds. It exists to make the literature findable and verifiable for researchers, clinicians, and the public. This guide explains what is in the library, how its citation integrity is tracked, and how to use it.
One thing the library is not: a recommendation. A large index of articles is a measure of how much has been written and indexed — it is not a measure of whether any treatment works. Read this page before drawing conclusions from a count.
Two kinds of entries
The library contains two distinct kinds of records, and the difference matters when you read it:
10,030
Imported articles
Bulk bibliographic entries generated from PubMed metadata. Each carries a PMID that has been checked against the live NCBI/PubMed API. These records give you a citation, a title, and a verifiable link — they are not editorially reviewed for clinical relevance, and inclusion is not an endorsement of any claim the article makes.
Curated / reviewed subset
A much smaller, hand-selected subset that has undergone deeper editorial review: placed in context, tied to a condition or compound, and assigned an evidence grade. Curation means an editor read the article and decided where it fits — it still does not mean ASH endorses a treatment, only that the article was judged relevant enough to annotate.
Imported is broad; curated is deep. An imported entry tells you a paper exists and where to find it. A curated entry tells you an ASH editor reviewed it and placed it in the evidence framework. Most of the 10,030 entries are imported, not curated — so do not read the total as a count of reviewed or endorsed studies.
How citation integrity works
Every entry carries a citation-integrity status so you can tell at a glance whether its identifier has been confirmed against the source database:
verified_pubmed
The PMID was checked against the live NCBI/PubMed API and resolves to a real paper whose title matches the record. Of the imported corpus, 9,902 of 9,903 unique PMIDs verified this way (99.99%). A wrong PMID is worse than no PMID — it looks like provenance while pointing at the wrong paper — so verification is tracked explicitly rather than assumed.
unverified_pending
The identifier has not yet completed verification, or did not resolve on the last check. The single fabricated identifier found in the imported corpus (PMID 39152982) was caught this way and quarantined. Treat an unverified_pending entry as a lead to confirm yourself, not as a settled citation.
The audit that produced these numbers, and the ongoing cleanup of the hand-built registries, are documented publicly on the PMID Audit Status page. Integrity is reported as an ongoing process, not a finished claim.
How to use the library
1. Search and browse by category
Entries are organized by topic — leech biology, salivary-gland compounds, clinical conditions, and reconstructive surgery, among others. Start from the research hub to browse categories or search by keyword, author, or condition.
2. Check the integrity status before you cite
Prefer verified_pubmed entries when you cite. For any entry, click through to PubMed and confirm the title matches the claim you are making — this is standard practice in evidence-based work and the verification step the library is designed to support.
3. Read the evidence grade, not just the count
For curated entries tied to a condition or compound, the evidence grade tells you how strong the underlying study design is. A library full of case reports is not the same as a library full of randomized trials. See how evidence is graded to interpret those badges.
What the library size does NOT mean
- Size is not a clinical recommendation. A count of 10,030 articles describes coverage of the literature. It says nothing about whether any treatment is safe or effective. Do not read “large library” as “strong evidence.”
- A listed article is not an endorsement. Inclusion means the paper exists and was indexed — not that ASH agrees with it, recommends what it describes, or considers its conclusions established.
- Imported is not reviewed. The bulk of the entries are imported bibliographic records, not editorially reviewed. Only the curated subset has been read and placed in context, and even curation is not a treatment claim.
- The library does not give medical advice. It is research infrastructure: a way to find and verify what has been published. Clinical decisions belong with a qualified clinician, not with an article count.
Related
PMID Audit Status
Public, ongoing transparency about citation integrity across the registries.
View status →How Evidence Is Graded
The Tier A/B/C framework and GRADE-aligned ratings used across the library.
Framework →