Health Subject Guide — PubMed Tutorial

Specify where to search for a term (for example in the article title or abstract) by placing a field tag after the term. Field tags must be outside of quotation marks.

Too many results?

• See the tabs for Choose and Refine Your Search Topic, Pick Search Terms, and Develop Search Strategies.
• Search for the population or key variables in the article's title by using the field tag [title] (e.g. diabetes [title]).
• Use the sidebar limits (filters) in PubMed to restrict your results by publication dates, age group, species, article types, language, etc.
• Search MeSH (see "Find Better Citations with MeSH" box below)
• If off-topic citations are appearing in your results, try adding terms to NOT them out
• For more information, view PubMed tutorial on search filters.

Too few results?

• Add alternate terms to describe the concepts you are searching ("strength training" OR "resistance training")
• Add specific examples of your topic (if you are searching for "chronic diseases", also include cancer, diabetes, COPD, etc. As another example, if you are searching for exercise, include walking, running, swimming, etc.)
• Remove extraneous terms from the search box (search for "cancer" rather than "cancer patients")
• Make sure that you are not putting words in quotes that are not true phrases
• Click the "Related citations see all" link for a list of relevant citations

To accurately limit by Publication Type, use search strings (groups of search terms), rather than PubMed filters.  Append the search strings below to your search.

Clinical Trials

Note: The PubMed filters for "clinical trial" finds only a small portion of the clinical trials in PubMed. There are two search strings that can be used to limit to clinical trials. 

Clinical Trials (less comprehensive, more precise)

AND (("clinical"[tiab] AND "trial"[tiab]) OR "clinical trials as topic"[mesh] OR "clinical trial"[pt] OR random*[tiab] OR "random allocation"[mesh] OR "therapeutic use"[sh])

Clinical Trials (more comprehensive, less precise)

AND ("randomized controlled trial"[pt] OR "controlled clinical trial"[pt] OR "clinical trials as topic"[mesh] OR "random allocation"[mesh] OR "double-blind method"[mesh] OR "single-blind method"[mesh] OR "clinical trial"[pt] OR "research design"[mesh:noexp] OR "comparative study"[pt] OR "evaluation study"[pt] OR "follow-up studies"[mesh] OR "prospective studies"[mesh] OR "cross-over studies"[mesh] OR "clinical trial"[tw] OR ((singl*[tw] OR doubl*[tw] OR trebl*[tw]) AND (mask*[tw] OR blind*[tw])) OR placebo*[tw] OR random*[tw] OR "control"[tw] OR "controls"[tw] OR prospectiv*[tw] OR volunteer*[tw])

Systematic Reviews 

AND (systematic[sb])

Systematic Reviews or Meta-Analysis

AND (systematic[sb] OR meta-analysis[pt] OR meta-analysis as topic[mh] OR meta-analysis[mh] OR meta analy*[tw] OR metanaly*[tw] OR metaanaly*[tw] OR met analy*[tw] OR integrative research[tiab] OR integrative review*[tiab] OR integrative overview*[tiab] OR research integration*[tiab] OR research overview*[tiab] OR collaborative review*[tiab] OR collaborative overview*[tiab] OR systematic review*[tiab] OR technology assessment*[tiab] OR technology overview*[tiab] OR "Technology Assessment, Biomedical"[mh] OR HTA[tiab] OR HTAs[tiab] OR comparative efficacy[tiab] OR comparative effectiveness[tiab] OR outcomes research[tiab] OR indirect comparison*[tiab] OR ((indirect treatment[tiab] OR mixed-treatment[tiab]) AND comparison*[tiab]) OR Embase*[tiab] OR Cinahl*[tiab] OR systematic overview*[tiab] OR methodological overview*[tiab] OR methodologic overview*[tiab] OR methodological review*[tiab] OR methodologic review*[tiab] OR quantitative review*[tiab] OR quantitative overview*[tiab] OR quantitative synthes*[tiab] OR pooled analy*[tiab] OR Cochrane[tiab] OR Medline[tiab] OR Pubmed[tiab] OR Medlars[tiab] OR handsearch*[tiab] OR hand search*[tiab] OR meta-regression*[tiab] OR metaregression*[tiab] OR data synthes*[tiab] OR data extraction[tiab] OR data abstraction*[tiab] OR mantel haenszel[tiab] OR peto[tiab] OR der-simonian[tiab] OR dersimonian[tiab] OR fixed effect*[tiab] OR "Cochrane Database Syst Rev"[Journal:__jrid21711] OR "health technology assessment winchester, england"[Journal] OR "Evid Rep Technol Assess (Full Rep)"[Journal] OR "Evid Rep Technol Assess (Summ)"[Journal] OR "Int J Technol Assess Health Care"[Journal] OR "GMS Health Technol Assess"[Journal] OR "Health Technol Assess (Rockv)"[Journal] OR "Health Technol Assess Rep"[Journal])

Weed out articles that are not research studies:

Commentary, Letters to the Editor, Editorials, and Reviews   ​

NOT (Comment[sb] OR Letter[pt] OR Editorial[pt] OR Review[pt])

Commentary, Letters to the Editor, Editorials, Reviews, and Case Reports

NOT (Comment[sb] OR Letter[pt] OR Editorial[pt] OR Review[pt] OR "Case Reports"[pt])

Because many articles identify the age of subjects using numbers (e.g. participants were ages 15-19), the only accurate way to search for age is to use the age filter. This requires a few steps. 

At the bottom of Filters sidebar, click: Show additional filters > Ages > Show

Reveal more specific age ranges by clicking "Customize".  Select the ages you want, and click Show. The filters are now showing. Don't forget to activate them from the Filters sidebar.

If you limit by age often, you may want to bypass the cumbersome filters. Age limiters can also be set by adding one or more of the following MeSH to your search.

birth-23 months: "infant"[mesh]

2-5 years: "child, preschool"[mesh]

6-12 years: "child"[mesh]

13-18 years: "adolescent"[mesh]

19-24 years: "young adult"[mesh]

19-44 years: "adult"[mesh Terms:noexp]

19+ years: "adult"[mesh]

45-64 years: "middle aged"[mesh]

65+ years: "aged"[mesh]

80+ years: "aged, 80 and over"[mesh]

The PubMed results screen provides a quick limit for Humans (see limiters in the left column). If you select this, PubMed will append the following to your search

AND "humans"[mesh]

You may notice a couple of surprising things when you limit to humans:

1) Animal studies will likely remain in your results. If an article discusses both humans & animals, it will be given MeSH for both. These human & animal articles will come up if you limit to either humans or animals.

2) The most recent studies disappear from your results. This is because they haven't been indexed (gotten their MeSH yet).

Limit to human-only articles without losing the most recent results by appending one of the search strings below to your search.

Weed out articles that are about animals and not also about humans

NOT ((animals[mesh] NOT humans[mesh]) OR rat[ti] OR rats[ti] OR mouse[ti] OR mice[ti] OR bovine[ti] OR cow[ti] OR cows[ti])

Or, if you want to get fancy, you can opt to search for articles about animals that do not include human & animal studies 

NOT ("Animals"[Mesh] NOT ("Animals"[Mesh] AND "Humans"[Mesh])  OR rat[ti] OR rats[ti] OR mouse[ti] OR mice[ti] OR bovine[ti] OR cow[ti] OR cows[ti])

(feel free to add additional types of animals to the title, such as monkeys[ti])

What are MeSH?

MeSH (short for Medical Subject Headings) are the most important part of the citation, despite being hidden from view until you click the "MeSH terms" link (beneath the abstract).

MeSH descriptors are s powerful because they are carefully chosen/controlled. PubMed's creators, the National Library of Medicine, select only one MeSH for each medical topic. This rule-of-one is important because even though articles use different words to discuss a topic, the MeSH will ALWAYS be the same.

Use MeSH when...

Different words describe a topic:

If you search for MeSH, you will find all the articles on your topic, even if the articles used different terms.

Searching for topics that are described in different ways is challenging.  For example, articles about weight lifting can use many different terms to describe this topic: weight lifting, resistance training, resistance exercise, power lifting, strength exercises, strength building exercises, etc. Some articles won't use any of terms for weight lifting, per se, but will only discuss specific type(s) of weight lifting exercises: squats, bench press, etc. 

As a searcher, finding all the terms on a topic can be frustrating. That is why you should use MeSH.

Every article in PubMed (not just the citation and abstract) is analyzed to find the best MeSH. An article about weight lifting will have the MeSH "resistance training" added to the citation, regardless of what term(s) the article used.

A term has multiple meanings:

Searching for MeSH solves the problem of multiple meanings because each MeSH has one-and-only-one meaning.

MeSH is particularly helpful when terms have different meanings. Consider AIDS--are you talking about the disease or a medical device, such as a hearing aid? How about running and cycling? Do you mean physical exercises or are you referring to running the laboratory, running equipment, cell cycling, load cycling, etc.

"Sign in to My NCBI" (link in upper right corner of PubMed) to:

• save searches
• create alerts (new citations will be sent to you weekly)
• highlight search terms in results
• store citations in permanent collections

Eleven new or revised interactive tutorials (or quick tours) on using PubMed are available from the PubMed Online Training page or scroll below.  The tutorials are brief and will ask you to complete actions.

For more advanced or comprehensive tutorials use the following tutorials produced by PubMed.