Advanced Searches on PubMed
The National Center for Biotechnology Information (NCBI) maintains and continually updates the PubMed database containing citation information on over 30 million publications to date. The resource is free and publicly available online to search exactly who is publishing in their respective research fields and the universities or institutes affiliated with the study. It also helps to keep track of an authors’ overall publication record. Simply searching an author name provides a nearly complete list of his or her publication record.
With a wealth of information readily available, knowing how to perform advanced searches on PubMed can help you quickly filter your search.
The PubMed Search Filters
PubMed provides a direct link to build advanced searches on their database. Through it, they provide a number of different filters which one can use to narrow their search.
The entire list of filters are:
| Affiliation [AD] | Date - Modification [LR] | Language [LA] | Secondary Source ID [SI] |
| Author - First [1AU] | Date - Publication [DP] | Location ID [LID] | Subject - Personal Name [PS] |
| Author - Identifier [AID] | EC/RN Number [RN] | MeSH - Major Topic [MAJR] | Supplementary Concept [NM] |
| Author - Last [LASTAU] | Editor [ED] | MeSH - Subheading [SH] | Text Word [TW] |
| Book [BOOK] | Filter [FILTER] | MeSH - Terms [MH] | Title [TI] |
| Conflict of Interest Statements [COIS] | Grant Number [GR] | Other Term [OT] | Title/Abstract [TIAB] |
| Date - Completion [DCOM] | ISBN [ISBN] | Pagination [PG] | Transliterated Title [TT] |
| Date - Create [CRDT] | Investigator [IR] | Pharmacological Action [PA] | Volume [VI] |
| Date - Entry [EDAT] | Issue [IP] | Publication Type [PT] | |
| Date - MeSH [MHDA] | Journal [TA] | Publisher [PUBN] |
There are many different filters one can use to search, and many of these can also be combined in the same search to narrow down the results further.
Definitions of PubMed Advanced Filters
To briefly review some of the acronyms: MeSH stands for “Medical Subject Headings”. These are essentially keywords that the National Library of Medicine uses to categorize certain publications. It’s a controlled set of vocabulary terms used to describe the content of the publication.
- Article Identifier is a unique identifier for the article itself. In the case of PubMed, this would be the citation’s DOI (Digital Object Identifier) for instance.
- The Create Date differs from the Entrez Date in that the former is when the citation record was first created. The Entrez Date was when the citation was actually uploaded or added to PubMed.
- EC/RN Number is a unique identifier for a particular ingredient, enzyme, or component. These are assigned by agencies such as the Food and Drug Administration (FDA).
- The ISBN is an International Standard Book Number similar to a book’s ISBN. This should also be unique (assuming the publication is from a book).
- Secondary Source ID is an additional field to accommodate outside sources for the publication (e.g. PubChem, ClinicalTrials.gov, etc.).
The remaining filters should be relatively straightforward, however, exact definitions for all of them can be found on the PubMed Help page.
Using the PubMed Advanced Search Filters
To use the filters, it’s as easy as adding the filter code to your search query. The general structure of your search should be:
[search term or query][FILTER]
For example, if you search “alzheimers[TIAB]”, this would return a list of citations that include the keyword “alzheimers” in both the title and abstract [TIAB]. If you wanted to search by author, you would type in “author[IAU]” or “author[LASTAU]” depending on if you wanted to search him or her as the first or last author.
To search by date, the format is:
YEARFROM:YEARTO[EDAT]
Here’s an example: 2008:2019[EDAT]
This would search for publications that were uploaded to PubMed (Entrez date) between 2008 and 2019.
To include the month, the format is:
YEAR/MO:YEAR/MO[EDAT]
Similarly, you can combine searches using the AND keyword:
[search term or query][FILTER1] AND [another search term or query][FILTER2]
Therefore, if you search “Smith[LASTAU] AND leukemia[TI]”, this would return a list of publications matching both crtieria: containing last authors whose names include “Smith”, and the title of the articles containing the word “leukemia.”
If you use the PubMed advanced search builder, you can simply select the appropriate filter from the dropdown menu. However, in practice, you may find yourself memorizing the more frequently used search filters if you’re trying to build lead lists - author, title/abstract, affiliation, etc. Once these are memorized, you can input those queries directly on the PubMed front-page or on our Search Pubmed tool. By using our search tool, you can combine the utility of these advanced filters with the ability to quickly export out contact information.
Building advanced searches on PubMed is relatively easy, and the filters provided can help you quickly narrow down the +30M citations. With a few practice queries, you’ll find yourself quickly utilizing the database to gather more targeted lead lists more effectively.