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Health Sciences Literature Searching: Conduct your search

Students and researchers in the health sciences often conduct comprehensive searches of the literature. The steps in this guide show how this process works.


CINAHL and PubMed are the two databases we focused on in this page.

Click here to access the complete list of BCIT databases


Do not use the "Free full text" or "Full text" filters. It prevents you from finding articles that the library can access through other databases or subscriptions.

Tips for searching databases:

  1. Search one concept at a time
  2. Map terms to subject headings
  3. Read the scope notes
  4. When in doubt, explode but do not focus
  5. Use keywords as well as subject headings
  6. Combine terms with Boolean operators
  7. Gather keywords and subject headings from relevant results
  8. Limit results
  9. Save results & save search history

Creating a Search

Compose a search by combining terms. 

Example question: Is handwashing effective in reducing hospital acquired infections?

 (connect terms)



(Combine different topics)

hand?washing AND "hospital infection*" Results contain both of the terms  fewer results


(combine synonymous terms)

"cross infection" OR "hospital infection" Results can contain any of the terms more results

("hand disinfection" OR hand?washing)


("cross infection" OR "hospital infection" OR "nosocomial infection")

Results include both topics using any of the terms connected by OR. fewer results

 Too Many Results?

  • Use limiters/filters
    • Limit by publication date
    • Limit to peer-reviewed articles
    • Limit by publication type (e.g., research, randomized controlled trials, systematic reviews)
  • If there are still way too many results
    • consider limiting your search by full-text only. 

Too Few Results?

  • Use truncation, and wildcard symbols (*, ?, etc. The chosen symbol varies by database.) Example search: nurs* - results: nursing, nurses, nursery, etc.
  • Choose a broader subject. Example: Change from corticosteroids to hormones, or change from pregnant women to all women.


  1. Look at the terms used in any key articles you found. Look at the abstract, subject headings or author-supplied keywords. Revise your search using some of these terms.
  2. Look at the reference list of any key articles found. 
  3. If you cannot find what you need in one database, try another one.
  4. Change your search. Adding keywords, focusing or removing some concepts.
  5. Searching takes time and practice. You may need to revise your search several times before you find what you need.

Identify the details of your topic in order to compose a PICO question.


Example Answers

Search Terms
MeSH* Keywords**
(Ex: illness, condition, age, gender, ethnicity)
hospital acquired infection cross infection nosocomial infection
(Ex: medication, diet, activity, or method)
handwashing hand disinfection   hand sanitation
Are you making a COMPARISON 
(Ex: alternate treatment, medication, or method)

What is the intended OUTCOME
(Ex: health status, delayed or eliminated illness)

reduced infection see first box see first box

Question (example):Is handwashing effective in reducing hospital acquired infections?

*MeSH (Medical Subject Headings) - set of terms used in biomedical databases to "tag" the subjects contained in articles.

**Keywords - text found in articles or article titles that describe the subject; similar topics; synonyms. (from The University of Texas at Arlington)

What are Search Limiters

Search limiters/filters restrict the number of results so they are more precise, they eliminate articles that do not fit your criteria.

Common search limiters/filters include: Date Published, Language, and Article Type.

Most databases have limiters/filters that reflect the needs of its literature. As health literature databases, CINAHL limiters and PubMed filters include patient information such as Age and Sex.

Many health science research projects will only seek to focus on articles from the past five or so years. Limiting you search based on publication date before finding an article that falls out of this date range is a good habit to form.

Limiters/filters in these databases

CINAHL's limiters are listed under the search bar and the subtitle "Limit Your Results". The most important ones limit the literature to date published, peer-review, and English language.

Look for the filters on the left side of the results page. The most important filters are Publication Dates, Article Types, and patient population.

"Publication Dates" retrieves articles that were published during the years you specify. You can immediately select articles from the last 5 or 10 years. If you click the "Custom Range" link, you can pick any range of years you like.

"Article Types" retrieves entries based on its type of research and its format.

"Sex" and "Ages" filter the patient populations in the literature according to their sex and age range.



There are a few other filters available in PubMed like "Species". Click the "Choose Additional Filters" link to see them. Experimenting with filters can drastically change your results.

Structured Process to Searching

You have your topic, you've thought about what you want to search and where you'll search... Now it's time to think about how to conduct the search. 

For the majority of health sciences searches:

  1. Start with CINAHL
  2. Search your concepts using a combination of subject headings and keywords, combined logically (i.e., use boolean)
  3. Search in additional databases. Note: A librarian can help you select the best ones for your question 

Use a "structured process" to search comprehensively to:

  • edit and refine your search as you go
  • keep things clear and easy to understand
  • make it easy for your reader to follow 

In the example below (from bottom to top, the CINAHL way), notice how a structured process to this search makes the strategy clear and easy to understand.

Example : What is the role of therapy dogs in nursing homes?