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Searching PubMed: Filters and Narrowing Searches

Created by Health Science Librarians

PubMed Field Tags

You can use field tags in PubMed to limit your search to only the specified fields of the citations. For instance, you can add a title field tag and only search for a word or words in article titles. Without field tags, PubMed defaults to searching every field of a citation. This means you're searching the article title, abstract/summary, author-supplied keywords, PubMed indexing terms, and other fields like author names, authors' institutions, journal names, etc.

If your search seems to have too many irrelevant results, using field tags can help narrow your search. To use field tags, add the code in brackets immediately following the search term. For instance, to only search for dogs in the titles of articles, you'd search for dogs[TI] in PubMed.

A list of common field tags is below: 

Citation Topic tags Other tags of interest

Author [AU]

Title [TI]

Publication Date [DP]

Journal [TA]

Volume [VI]

Issue [IP]



Title [TI]

Title/Abstract [TIAB]

Text Words [TW]

MeSH Terms [MH]

MeSH Major Topic [MAJR]

MeSH Subheadings [SH]

Supplementary Concept [NM]

Pharmacological Action [PA]

Subset [SB]

Filter [FILTER]

Language [LA]

Publication Type [PT]

Affiliation [AD]

Entrez Date [EDAT]

First Author Name [1AU]

Grant Number [GR]

Use Filters to Focus the Search

Use the filter options available in the left sidebar of the search results page to focus the search.

Important: The "Free full text" filter does not include UNC-CH journals subscriptions. The "Full text" filter is not an accurate limit to UNC-CH journal subscriptions. Use the Find @ UNC button to find full-text articles.

Show Additional Filters

The default list of filter categories in the left hand sidebar does not include all options. Click on the link labeled "Choose additional filters" to add categories to the list. Filters are available to focus your search results by article types, text availability, publication dates, species, languages, sex, subjects, journal categories, ages, and search fields. Click on the boxes to activate the filters. For more filter options click on the additional filters option.


Type of Article, Species, Sex, and Ages filters are based on terms added by indexers. When these filters are selected they remove very recent articles that have not yet been indexed. Always look at the most recent search results before adding these filters.

Activated Filters Display on Search Result Pages. Filters stay selected during the current search session until you change or clear them.

Once the filters are selected on the above screenshot they appear as boxes on the left hand of the screen on the results page. Tick those boxes to show the changes in the search results.



Go to PubMed Help to learn more about using filters. 

Article Types

Research Study Filters

Add options to the "Article types" list by clicking on the "Additional Filters" link on the left of search result screen and selecting ones you want to use.

Therapy, intervention, and prevention search results can be limited to articles reporting clinical research by selecting Clinical Trial, Meta-Analysis, Randomized Control Trial or Systematic Reviews from the "Articles types" list.       


You can then select the filter you want. Following that check the left hand box to have it appear in the search results.

  • Clinical Trial: "Work that is the report of a pre-planned clinical study of the safety, efficacy, or optimum dosage schedule of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques in humans."
  • Meta-Analysis: "Works consisting of studies using a quantitative method of combining the results of independent studies (usually drawn from the published literature) and synthesizing summaries and conclusions which may be used to evaluate therapeutic effectiveness, plan new studies, etc. It is often an overview of clinical trials."
  • Randomized Control Trial: "Work consisting of a clinical trial that involves at least one test treatment and one control treatment, concurrent enrollment and follow-up of the test- and control-treated groups, and in which the treatments to be administered are selected by a random process, such as the use of a random-numbers table."
  • Systematic Reviews--retrieves "citations identified as systematic reviews, meta-analyses, reviews of clinical trials, evidence-based medicine, consensus development conferences, guidelines, and citations to articles from journals specializing in review studies of value to clinicians." Systematic Review Filter Search Strategy

Other Research Article Type Filters

  • Comparative Study--"comparison of outcomes, results, responses, etc for different techniques, therapeutic approaches or other inputs."
  • Evaluation Studies--"studies determining the effectiveness or utility of processes, personnel, and equipment."
  • Research Support, ...--"organizational source for funding of research activity"

Quoted definitions are from the PubMed MeSH Browser

Clinical Queries

Clinical queries makes it easy to find research-based articles in Pubmed.   Click on "Clinical Queries" from Pubmed homepage.

Enter a search term/search terms in the box.  Click the Search button.

PubMed Clinical Queries

Clinical Study Categories displays results by diagnosis,etiology, therapy,etc. Use the drop-down menus to change the category or scope.  Select a Category: Therapy, Diagnosis, Etiology, Prognosis, or Clinical prediction guides.  Then, select a Scope: Narrow (specific search) or Broad (sensitive search).

Systematic Reviews displays citations identified as systematic reviews, meta-analyses, reviews of clinical trials, evidence-based medicine, and/or guidelines.

Medical Genetics displays citations focused on diagnosis, management, genetic counseling, and related topics.