In this walkthrough tutorial, we will cover how to use Embase to find articles on the sample topic “use of zolpidem for the treatment of insomnia.” Complete the steps described along with this guide to practice using Embase.
Please note: Embase is updated constantly, so don’t worry if your results don’t match the ones in the images exactly.
Embase can be used for quick Google-like keyword searches, which you can do from the homepage. (Need a refresher on translating research topics to database search phrases?)
The good news: Quick Search is a fast way to access scholarly publications on a topic.
The bad news: (1) with over 28 million citations in Embase, you are likely to retrieve too many results, many of which may be irrelevant and (2) because of differences in terminology use, you may miss relevant results.
For best results, always start your searches with the Emtree Query Builder.
Many databases, including Embase, allow you to use subjects as well as keywords. What is the difference?
Keywords are the words we tend to use in daily life: "heart attack," "cancer," etc. You can simply enter them in a database's search boxes. However, when you search for a keyword, you are depending on the authors of an article using the same keywords you did. If so, your keywords will match the words used in the article's title, abstract, etc. and it will show up in your search results.
Subjects are the field's professional terms: "myocardial infarction," "neoplasms," etc. Subjects are assigned to each citation by indexers to ensure your searches catch all articles on a topic even if the authors did not use the same keywords you did. For example, if you search for "lung cancer" but the author used the phrase "pulmonary neoplasms" instead, you may not find that article with keywords, but you will find it if you search for the subject "lung cancer."
Subjects in Embase are called Emtree terms (like MeSH terms in PubMed/MEDLINE). Each citation included in Embase is reviewed by an indexer and assigned Emtree terms that describe it. Although Embase strives to use naturalistic (keyword-like) subjects, you can use the Emtree to find the exact subjects that correspond to your topic.
Access the Emtree by clicking on "Browse," located in the top menu from the homepage, then selecting the "Emtree" option.
To use Emtree, type a keyword (one at a time) in the search box and click on "Find Term" or press enter on your keyboard.
You will get a list of Emtree terms in the results that match your keyword.
Click on a term to see its associated options. In this case, we will click on "zolpidem."
Each Emtree entry will include a hierarchy (tree) that shows where this term falls in relation to the other Emtree subjects. Terms above and to the left of this term are more general, any terms below and to the right are more specific. You can switch between the levels to be more or less specific. For this search, we will keep this term as is.
The Emtree entry will also include information on the history of the term (such as when it was added to Emtree), any synonyms the term has, and, if it is a chemical substance such as zolpidem, the CAS Registry Number.
Before you add the term to your search, examine the "Extend your search" options. "Explosion" will also include every subject in the hierarchy that is more specific than yours. "As major focus" will only search for publications that include your term as (one of) the main topic(s). For now, we will uncheck both boxes.
When you are ready, click on the “Add to Query Builder” button. (Note: because zolpidem is a drug, we have the option of selecting "Take this query to Drug Search." If you want detailed information on a drug, such as the route of administration, select this option. Otherwise, conduct a standard search, as we will do for now.)
The term will be added to the Query Builder section at the top of the page. Briefly, the "Add to Query Builder" button will change to "Successfully Added."
Repeat this process for every keyword in your topic. Go ahead and do it again now for insomnia, but this time select "Explosion," since we want to include subtypes of insomnia too. When you are finished, your Query Builder should look like the image below:
Note that, by default, Embase will place an “AND” between your terms, but you can change to a different Boolean operator manually.
Before running the search, always double-check the search phrase to make sure everything is correct and don’t forget to add/edit parentheses as needed to keep related concepts together. Once you click “Search," you will have to start over at the Emtree if you want to search for more terms.
When you are ready, you can select "Take this query to Advanced Search" to modify the search or add limits such as language, gender, or age groups - but you can always modify the search later. For now, we will simply click "Search."
Your Embase results will be listed in order of publication date by default, with the most recent articles first. (Again, don't worry if your results don't match the ones in the images exactly - Embase is frequently updated.)
(Click on the image to enlarge it.)
Let's go ahead and modify the results now. At the left of the results is a list of available filters. Filters are useful for applying exclusion criteria to your searches and for limiting the number of results. Click on a filter to see the available options. For this search, let's limit the results to studies from 2010 to the present (under the "Publication Year" filter) and adults (under the "Age" filter).
Click "Update" when you have selected the filters you want.
(Click on the image to enlarge it.)
Notice we decreased our results using filters from an overwhelming 1,900+ articles to a more manageable 194 articles.
Each item in the search results includes a citation with the article and journal titles, authors, and full journal citation information (including volume, issue, and page numbers), and is accompanied by "Abstract" and "Index Terms" tabs. Click on one of these tabs to view a summary of the article or the subjects associated with it.
You can use the options at the top of the results to sort them in a different way, such as by relevance or entry date.
In addition, you can combine your searches with the Boolean operators AND and OR using the search history at the top of the page.
A great way to use this feature is to search for one Emtree term at a time to keep things simple (especially when you are using many terms and/or are also using synonyms), then combine your searches instead of including lots of Emtree terms in one search phrase. In our sample search, for instance, we could have searched for zolpidem first, then run a separate search for insomnia, and then combined the two searches with the Boolean operator “AND” using the search history, as an alternative to using both terms in the same search phrase like we did.
If you access Embase through FIU, you may see a “Find It @ FIU” icon or link with each search result:
- or -
Click on the icon or link to get the article from the FIU Libraries.
If the “Find It @ FIU” icon is not available for a particular result, you can click on the "View Full Text" link below the result to go to the publisher's website.
In addition, you can use the "Find It @ FIU" citation linker on the library homepage to check for access to an article through the FIU Libraries.
Remember: you must log in through from the library homepage to have access to the articles from off-campus locations.