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Nursing Research Guide

PICO(T): Framing the Research Question

The PICO(T) framework is a consistent "formula" for  developing literature search strategies. PICO(T) stands for:  

P Population/Patient  (the population/patient you intend to study)

I Intervention (the drug or therapy that is intervening)

C Comparison/Control (comparing the intervention with another drug, therapy, or placebo)

O Outcome (did the intervention provide relief)

(T) (optional) Time element or Type of Study

When you put all 4 ideas into one clinical research question, you end up with a focused topic.

Example:  You decided to research the chickenpox vaccine and risk involved with the vaccine.  The PICO question format might be: What are the adverse effects in infants who receive the chickenpox vaccine?  The Population to be studied is infant;, the Intervention is the vaccine; the Comparison to be studied are infants who do not receive the vaccine; and the Outcome to be studied is the adverse effects in those vaccinated.

Search Tips

Phrase Searching " "

When multiple words are placed  in a single search box, a database search engine will do one of two things--by default, the search engine will either:

1.  Search for those words as a phrase.  Meaning it will search for them side-by-side, next to each other and in that exact order ONLY,


2.  Automatically place an implied Boolean `AND` between the words and search for each word separately.  It will retrieve only articles that contain both words, including those that are next to each other...but in addition it will also retrieve articles where the words are found separately in different places within the article.

By default, most of the library databases will search for multiple words as a phrase.  On the other hand Google and most online search engines will insert the implied AND between each word.  To remedy this problem, try using double quotation marks around the phrase you want to search "infection control" and place a Boolean `AND` between words if you wish to search for them separately, "hand washing" AND "infection control." 


An asterisk can be used in many databases as a truncation symbol. With it your search will retrieve a root word with multiple endings: child* will find child, children, childhood, etc.

Parentheses ( ) 

Parentheses nest words so the database searches them in the right order:  “infection control” AND (handwashing OR “hand washing”) tells the database to look for the words in ( ) first and then to combine that set with "infection control."

When looking for books or articles try to narrow down your keywords.  For example: search the terms hand washing AND infections.  The results returned will have all of the terms hand washing and infections somewhere in the citation.  Look for the hyperlinked subject terms to lead you to more items with this same subject; for example Professional Compliance  AND handwashing are subject terms--Controlled vocabulary supplied by the database, MeSH.  The results should be more exact  on your topic which means less searching.

Combine terms with AND, OR, NOT, NEAR:  

  • hand washing AND infection control → Narrow results (Reduces the number of search results by requiring both terms to appear in the article)
  • handwashing OR hand washing → Broad results (Expands the number of search results by expanding the possible matches to include either one or the other term, or both)
  • handwashing NOT soap → Narrow results (Reduces search results to omit references to articles with certain words that have nothing to do with your topic)
  • hand NEAR washing → Narrow results (Reduces search results by requiring two words to appear near one another in the articles)

Putting it all together...

Put it all together to make a sophisticated search: (handwashing OR hand washing) AND (infection control)

Literature Reviews

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