Database Searching in the Health Sciences

After selecting the databases you will use comes the most important part - to develop a search strategy. Your search strategy will guide you in finding relevant information in your chosen databases. The key to this process is identifying and utilizing a combination of keywords, subject headings, search operators, and limiters.

You do not need to include all of these strategies as part of your search, but some of the suggestions below can be useful when putting together more complex searches. 

The most important parts to understand are use of Developing a Search Strategy, brainstorming Keywords and synonymous (and possibly Subject Terms/Controlled Vocabulary), and putting the search together with the appropriate Boolean Operators.

Break your research topic down into the most important and main concepts.

Research question: In patients with established cardiovascular disease, do stains compared to no treatment or placebo prevent cardiovascular events?

After breaking down your main concepts into keywords, now consider synonymous terms. There are different ways to describe the same concept.

• Think about concepts and terms that others would use to describe your topic, including scholars.
• Consider outdated terms or terms that are no longer acceptable today. These terms may still be prominently reflected in the literature.

How to find synonyms

Example with synonymous terms

Subject terms or controlled vocabulary, are specific words or phrases that were assigned by a database to describe the article, book, or record. Library databases use searchable thesauri to arrange these subject terms.

• You can think of these as the "hash tags" used by a database to organize it's content, and make it easy to find all results about a specific subject. It is possible to search for articles using subject terms from database thesauri, rather than using keywords. 
• Since subject terms reflect the main focus of the record, searching by subject can be a rapid way to narrow results to a particular topic. 

A systematic search will use a combination of both keywords and subject terms/controlled vocabulary for a comprehensive literature search.

Boolean operators are words (AND, OR, NOT) that expand or narrow search parameters when using a database.

Example

Phrase searching is looking up phrases rather than a set of keywords in random order. By using phrase searching, it narrows search results by being precise about how you want the words to appear. Databases can use different symbols to search a phrase, however the most common way to search is with "quotes around the phrase".

• For example, if you are searching for information on patient satisfaction then you are probably looking for those two words to appear right next to each other, with no other words in between, in the text of the document. To make sure that the database searches this correctly you can put quotation marks around your search term and force the database to search this as a phrase - "patient satisfaction".

• Use caution when using many phrase searches since if you put many words in quotations the database might not not find any results. Try to use only established phrases that can be expected to be used by authors.

"Patient satisfaction" AND ("wait time" OR "time factors")

Truncation allows you to broaden your search by including alternative word endings and spellings. Most often asterisk (*) is the truncation symbol for databases and placed at the end of the root word.

For example, nurs* would find nurse, nurses, and nursing.

Wildcard symbols can broaden a database search by including alternative spellings within a word.

• Asterisk wildcard (*) - Is used between words where variations may be possible. Example: "evidence* practice" can return results such as, "evidence-based practice".
• Question mark wildcard (?) - Is used to replace an unknown character. Example: wom?n will show results for women or woman.
• Hashtag wildcard (#) - Wildcards allow you to broaden your search by including alternative spellings within a word. So is colo#r would bring results for color and colour.

Check in specific databases to see the suggested wildcard and truncation methods:

• EBSCOHost Wildcard and Truncation Symbols

• Using Wildcards and Truncation when searching in ProQuest

• PubMed Wildcards

• Web of Science Wildcard and Truncation

Field Codes are a specific part of a record in a database. Some of the most common fields that can be used in database searching include author, title, subject, and abstract.

Look for drop down boxes or menus to select in a database to select the field you want to search. The default field for most databases is usually keyword or all fields. By keeping this default, the database will search in any indexed field. But using specific field codes in combination with other search techniques can produce more precise searches.

Proximity or Adjacency Operators are used to narrow searches by finding words that are next to, near, or within a specified distance from each other. While not always needed, it can be used when Boolean operator searches are not narrowing down a search.

Different databases uses different proximity operators. The most common operators are either a letter (N or W) or word (NEAR), followed by a number that specifies the number of words between each search term. To make sure certain words are near or next to each other, adjust the number you search - so the lower the number, the narrower the search. 

Proximity Operators by Database

physical therapy is the search term and 3 is the number of words that fall between exercise and therapy.