Topic: Systematic Searching for Evidence Synthesis

CINAHL is a database that searches the nursing and allied health literature. Our access to this database is on a searching platform called EBSCOhost. On this platform, you use the the drop-down menus next to each search box to tell CINAHL where in the information about the source (the database record) you want it to search. This page covers many essential aspects of constructing a systematic search in CINAHL on EBSCOhost.

CINAHL, like many research databases, has its own controlled vocabulary, or standardized language, that it uses to label sources. The controlled vocabulary in CINAHL is called CINAHL Subject Headings. CINAHL Subject Headings, like other controlled vocabularies, are arranged in a hierarchy of terms. Generally, the most narrow possible relevant term in the hierarchy is assigned to a reference.

In the database records, these terms are displayed in the Subjects field. You can do a keyword search in the Subjects field or have CINAHL execute an exact match search. See Designing a Systematic Search in CINAHL further down this page for both options.

To search the Thesaurus for your topic:

1. Select CINAHL Subject Headings in the top navigation bar.

2. Type a word or phrase expressing just one idea in the box, then click the Browse button.

3. Click on the term that seems the closest match for your topic to see more details about it. If CINAHL prefers a different term than you searched (in this example, Stress Disorders, Post-Traumatic vs. PTSD), it will tell you to Use that controlled vocabulary term instead.

4. Clicking on a subject heading shows its place in the hierarchical tree. A plus sign next to a narrower term indicates the tree gets more granular underneath that term.

The scope note defines the term and may suggest related terms.

Truncation

Truncation is searching for any ending of a word. In CINAHL, use an * (asterisk) to replace one or more characters at the end of a string of letters. For example, mindful* finds mindful or mindfulness.

Wildcards

Wildcards can replace one or more characters. CINAHL offers three different wildcard options.

* (asterisk): In addition to truncation, the * can be used within a word to find multiple characters. For example, hea*one finds headphone, headstone, or hearthstone.

# (hash or pound sign): The # can be used for words where an alternate spelling may have one extra character. For example, p#edatric finds pediatric or paediatric.

? (question mark): The ? replaces only one unknown character in a word. For example, ne?t finds neat, nest, or next. The ? can't be used at the end of a string of characters; for that, use the * to truncate.

Single Words

In CINAHL and other databases on the EBSCOhost platform, a single word should be enclosed in quotation marks to avoid the database automatically searching for plural, possessive, and some other forms. For example, teach will search for teach OR teaches. "teach" searches only that exact string of characters. 

Phrase Searching

CINAHL requires you to use quotation marks around phrases to ensure the words are searched next to each other in that exact order. For example, if you're interested in low back pain, you need to search for "low back pain" if you want that to be the exact phrase found in your results. You can use truncation and other special characters inside the quotation marks, so you can also try "low* back pain" to ensure you get articles about lower back pain.

Proximity Searching

In proximity or adjacency searching, you can tell the database to look for words near each other in a variety of ways. It's essential when you do this type of searching that you use parentheses to group terms accurately!

Near, which uses the letter N, is one proximity operator. Near finds words if they are a maximum of a certain number of words apart from one another, regardless of the order in which they appear. You decide the number. For example, teaching N3 strateg* will find results that have a maximum of three words between the beginning and ending terms. You'll find results that mention teaching strategy, teaching strategies, or strategies often used for teaching. Note that you can use truncation and other syntax when employing proximity searching. That means you could also try something like mindfulness N5 "classroom management" or even, using parentheses to properly group your keywords, mindfulness N5 (anxiety OR depression).

Within, which uses the letter W, finds words if they are within a certain number of words of one another, in the order in which you entered them. For example, class* W2 manag* would find classroom management, classroom must be managed, but not managing your class.

You don't have to do proximity searching! But it can save you a lot of typing and create cleaner searches that are easier to read.

Some helpful terminology here: a database includes many records. Each record is a collection of information about a single item, such as an article. Records are made up of fields, sections of the record that provides a specific piece of information about the item described (the title, the author, the abstract, etc.). Which fields interest you, and how they're searched, varies from database to database. Field codes, like AB and TI, tell the database which fields to search, and how to do so.

In CINAHL, you'll likely want to search the following fields:

For your keywords or free text terms:

• Abstract (or AB) searches the abstract summaries
• Title (or TI) searches in the document title

For controlled vocabulary terms from the CINAHL Subject Headings, there are two approaches: a simpler but less exact strategy, and a complex but more systematic approach. They use different field codes, even though both search the Subjects field.

Option 1: If you've incorporated all the relevant controlled vocabulary you found into your keyword search strings, you can use the SU field code to perform a search within the Subject Heading field that operates like a keyword search. If it finds one of the words in any subject heading, not just the ones you identified in your CINAHL Subject Headings searches, it will return results that match. This means the search will be less precise, leading to more "noise," or irrelevant search results. This option is demonstrated first below.

Option 2: For a more systematic approach, which looks only for the exact controlled vocabulary terms you choose, you would leave out the Subjects (SU) line in the image below and construct the search for those terms in CINAHL Subject Headings. That's demonstrated next.

In general, your best strategy in any database is to set up each main idea as a single search string in each desired field, then combine those main idea searches with AND. If you're using Option 1, compose your search like this, using the exact same search statement (this OR this OR this) in each row.

After you've completed all your main idea searches, go to the Search History link (under the search boxes) and combine all the main ideas using AND.

Option 2:

For this approach, you'll still execute a keyword or free text search as shown above, but only for the TI and AB fields. You'll build a separate search for controlled vocabulary for each concept within CINAHL Subject Headings. Then you'll combine your TI/AB search and subject headings search for that concept together using OR. Once that's complete, you'll use AND to combine your main ideas.

In CINAHL Subject Headings, locate the terms you'd like to include in your controlled vocabulary search. To select a term, check the box to the left of it. CINAHL assumes you want to include all narrower terms, a function it calls Explode; if you don't want to do that you can uncheck it the box that pops up under Search Database button. You can also check the box under Major Concept to search a term as an important, or starred, term in the Subjects field. In the image below, CINAHL will search for Stress Disorders, Post-Traumatic as a Major Concept, excluding any narrower term. If that's all the controlled vocabulary terms you want for this main idea, click the Search Database button.

This is what a CINAHL Subject Headings-constructed controlled vocabulary search looks like in CINAHL.

In the Search History, you can then combine it with the matching keyword search (AB/TI) using OR.

In some cases, you'll want more than one subject heading. First, search for one of them. In this image, Mindfulness is selected, and it's set to explode, so Self-Compassion will also be searched (using OR).

Now click Back to Term List.

Scroll to the bottom of the term list and click Browse Additional Terms.

Search for another term. CINAHL banks prior selections to make it easy to OR them together. 

You can continuing checking boxes -- selecting terms and how you want them to be searched -- until you've checked all the controlled vocabulary you want to include. When all the terms you want are displayed, click Search Database. Combine selections with OR is the default. All the field codes will be applied automatically by CINAHL.

Finally, you'll combine your main idea searches with AND as in Option 1.

To export all results from an CINAHL search, up to 25,000 citations, tap the Share button at the top right of your search results. At the bottom of the pop-up box, choose the link under Export results.

Leaving the Email from box as is, enter your email in the Email to box. Under E-mail a link to a file with citations in: choose RIS Format. Then tap the Send button.

Shortly you'll receive an email containing a link to a zip file. When you download and extract the zip file, the RIS file will be inside. You can import the RIS file into the citation management tool of your choice.

To view your search history during a CINAHL session, select Search History under the search boxes.

On the Search History/Alerts page, choose Print Search History.

Once it's displayed for printing, you can copy the text on the page and paste it into a document or spreadsheet. It may require some cleaning up to be conveniently readable.