Module 3: Exploring MeSH for Expert Searching

In this module, we’ll follow an example search to explore how to take more control of your literature searches. We’ll investigate the MeSH terminology using the MeSH Database, and we’ll craft searches term-by-term.

Searching MeSH

Let’s explore how we might search for literature related to treating sleep problems in menopause by exploring these topics in MeSH.

First, search the MeSH Database for sleep disorders. Do this now.

Now you should see the MeSH Database results. Usually, your best term is at the top of the results. 

Quiz:

Scope Notes

Click on Sleep Wake Disorders to view its record in the MeSH Database. Notice at the top of the record there is a description of the concept.

We call this a "Scope Note." A scope note may or may not be the dictionary definition of a term. A scope note describes how we use the term in MeSH to describe biomedical information resources.

The scope note can help you decide if this is the right term for your search. The term Sleep Wake Disorders seems to be the right concept. But is it specific enough?

The Hierarchy

Because the PubMed database is vast, you will want to find the most specific terms appropriate to your search without eliminating relevant records.

After reviewing the scope note for a concept, scroll down the MeSH Database record to explore the hierarchy and determine if there is a more specific term that might be better for your search. 

Scroll down now to view the hierarchy for Sleep Wake Disorders:

In the case of Sleep Wake Disorders, this concept exists in several places in the MeSH tree. The narrower terms are categorized into Dyssomnias and Parasomnias in two of the branches. Under the branch for Pathological Conditions, Signs and Symptoms, there is just one narrower term: Sleep Deprivation.

A search of a broader term like Sleep Wake Disorders will automatically search all of the narrower terms underneath it, in every branch of the tree. The term is added to the PubMed records, not a tree location, so there is no way for our indexing process to specify which conceptual branch is intended.

It is therefore not possible to specify which conceptual branch you intend to search. This is another reason to be as specific as possible when searching while being mindful of what you might be eliminating.

Let’s say that, after exploring these concepts, we decide to keep our search for Sleep Wake Disorders broad for now, including all these more specific concepts. We don’t yet know how specific the indexing will be for articles of interest. And since we haven’t run a search yet, we don’t know how many records we’ll retrieve. But we’ll keep this hierarchy in mind in case we discover that we need to narrow our scope.

Let’s look at other ways we can refine our search without specifying the type of Sleep Wake Disorders we might be interested in.

Subheadings

We can specify an aspect of a topic of interest using subheadings (sometimes referred to as "qualifiers"). Scroll to the top of the record to review the subheadings.

The subheadings you see in a MeSH database record are ones that could be attached to a MeSH heading. 

The term Sleep Wake Disorders and its narrower terms have many different subheadings applied:

Select the subheadings you wish to search using the checkboxes and add them using the PubMed search builder in the upper right of the screen.

We're interested in treatment for sleep disorders, so let's select therapy and include it in our search. 

Click the box next to therapy and then click the "Add to search builder" button: 

Notice that the search string "Sleep Wake Disorders/therapy"[Mesh] is added to our search. This will retrieve any records indexed with Sleep Wake Disorders/therapy as well as all records with any specific Sleep Wake Disorder with a therapy subheading to our search.

A note on MeSH search tag variations

Just like MeSH preferred terms or headings, subheadings have a hierarchical structure. In fact, some of the subheadings you see listed on this record are narrower or indented terms under other subheadings. Explore the subheading hierarchy on this table. 

Quiz:

Our second concept

Let’s leave our sleep disorder topic for now (our PubMed Search Builder will keep our search as we continue) and move on to the other aspect of our search: menopause.

Search for menopause in MeSH:

Quiz:

Again, explore the hierarchy at the bottom of the record, both to ensure that you are using the right level of specificity for your search and to understand what terms are being automatically included.

Quiz: 

Let’s use the broader term, Menopause, for this example search. But let’s try a different way to restrict our results to only highly relevant records.

MeSH Major Topic

Another option for narrowing your search retrieval using MeSH is to use the option "Restrict to MeSH Major Topic," which is found below the subheadings on the MeSH Database record:

This is the same feature we introduced in Module 2 using the [majr] tag. This option allows you to use a broader topic in your search, but limit to articles where that topic was determined to be a major point of the article.

Select the checkbox next to “Restrict to MeSH Major Topic” and click the "Add to search builder" button in the PubMed Search Builder, in the right column.

Note that the MeSH heading is added to your search with the tag [Majr] for Major Topic. You should have a combined search: 

("Sleep Wake Disorders/therapy"[Mesh]) AND "Menopause"[Majr]

Let's run this search for records that have MeSH terms for therapy for Sleep Wake Disorders and for Menopause as a major topic. 

Click the "Search PubMed" button. 

Exploring MeSH Through Your PubMed Results

You should now see PubMed results. 

Our results for our initial PubMed search of ("Sleep Wake Disorders/therapy"[Mesh]) AND "Menopause"[Majr] are a very reasonable set to review: As of February 2023, there are fewer than 300 results.

Look through the results and see how these articles are described in the MeSH indexing. You should only see records that have MeSH terms for sleep disorders and a term for menopause as a major topic. Major topics are indicated with an asterisk (*). Click here for more information on “Why do I sometimes see the asterisk applied to the heading, and sometimes to the subheading?”*.

Look for the article title, "The efficacy and safety of acupuncture for perimenopausal insomnia: A protocol for a network meta-analysis." Notice that its MeSH terms include Perimenopause* and Sleep Initiation and Maintenance Disorders/therapy*. 

Quiz

Exploring MeSH Through Your PubMed Results

Often by exploring results that are relevant to your search, you may find other MeSH terms to search.

For example, here is another relevant article in our search results, "Effects of forehead cooling and supportive care on menopause-related sleep difficulties, hot flashes, and menopausal symptoms: a pilot study," where in addition to the term Menopause, there’s also the term Hot Flashes:

There might be articles about hot flashes and sleep that might be worth exploring in addition to this set of records. A thorough search of MEDLINE records for a topic often involves a series of explorations of the terminology using the MeSH Database and the indexing of other relevant results in PubMed.

We’ve now explored quite a bit of the MeSH Database record, but there is more. Click here for a “Section-by-Section Tour of a MeSH Database Record”*.

Considering the non-MEDLINE set

We’ve now tried some techniques for searching MEDLINE records with MeSH. Now recall that not all PubMed records have MeSH. As we discussed in Module 2, for maximum control, you may wish to split your search into those searches using MeSH (for MEDLINE records) and searches using keywords (for non-MEDLINE records). You can search the MEDLINE and non-MEDLINE records separately.

• For MEDLINE records, use MeSH terms by creating your search from the MeSH Database, as described above, or by tagging:

menopause[mh] AND sleep wake disorders/therapy[mh]

• For non-MEDLINE records, exclude the MEDLINE subset using NOT medline[sb]:

sleep AND menopause AND (treatment OR therapy) NOT medline[sb]

[sb] is a search tag for “Subset.” The MEDLINE subset is the set of PubMed records that come from MEDLINE journals and have been indexed with MeSH. (Note that these searches are for demonstration and have not been tested for sensitivity.)

Remember that you can view your full search details, including the term variations that PubMed is adding to your search, by clicking Advanced and scrolling to History and Search Details. Try this now with the PubMed search for menopause sleep disorder therapy. The Translations section breaks down your search by concept.

You can also test or combine your searches using the search numbers:

Exercise:

By using the MeSH Database, construct a search of MEDLINE records in PubMed for articles that discuss treating sleep-wake schedule disorders with melatonin. Answer the following questions about the search:

Suggested strategy for this search: ("Sleep Disorders, Circadian Rhythm/drug therapy"[mh]) AND "Melatonin"[MeSH] 

Example search: ((sleep schedule OR sleep disorder OR circadian rhythm OR night shift) AND melatonin AND (treatment OR therapy)) NOT medline[sb]

You have completed the Exploring MeSH for Expert Searching activity. Close both tutorial windows to exit this guide.