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FCS 463: Nutrition Care Process: P.I.C.O.

Searching Strategies - why bother?

   "From the standpoint of general effectiveness in searching,... the searcher with the widest range of search strategies available is the searcher with the greatest retrieval power."

Marcia J. Bates,THE DESIGN OF BROWSING AND BERRYPICKING TECHNIQUES FOR THE ONLINE SEARCH INTERFACE, Graduate School of Library and Information Science, University of California at Los Angeles


Formulating a research question


Tutorial| How to build an evidence based research question.

"PICO" is a nemonic acroynm to help you remember the elements that should be identified when formulating a question and search strategy to retrieve the most recent, pertinent, and valid research studies to guide decision making that results in quality healthcare.

P = Population (usually identifies a specific population with topic of interest)

I = Intervention

C = Comparison

O = Outcome

Formulating a question


PICO is just an acronym.

PICO helps you remember which key elements must be identified when formulating a research question and which elements to include in a search strategy so that you retrieve the most recent, pertinent, and valid research studies to answer your research question and to know with reasonable certainty that you identified the best evidence to guide decision making and advance quality healthcare.

Researchers identify a specific population, therapy/intervention/procedure/test, sometimes a comparison with another intervention or placebo, and the specific desired outcome that they hope will be obtained when using the intervention and comparative placebo.  A choice of a valid study design will factor in all of these elements and incorporate some kind of measurement of outcome and results.

 Formulating a PICO question | Tutorial

  P = Population      

Commonly a population with a topic of interest, e.g. obese adolescent, diabetic adolescent

I = Intervention    

Includes therapies, treatments, procedures, tests

C = Comparison     

Includes interventions, therapies, procedures, tests, treatments, placebo

O = Outcome   

Once you have identified keywords that MUST be included in your search in order to retrieve relevant articles, a rigorous search across multiple databases,and a search by author's identified as researchers on your topic will help to confirm whether or not relevant research has been reported on your specific PICO question. 

Below find a sample formulation of a research question not yet fully developed and refined.  It is a  good beginning, but too board. Background reading will inform the novice on how to further add the necessary specifics to this question. Keep a list of keywords and their synonyms as develop a search strategy for use in the research databases.

Review the following research question. What elements are identified?  What is the population with topic of interest, intervention, comparison intervetion or placebo, and the measured outcome?

PICO Question #1

 In the obese adolescent, is diet and exercise more effective in reducing weight compared to exercise alone?



Search strategy to consider in PubMed. First search your population and your intervention, per expert Cochrane searchers.

Default Search Strategy              obesity exercise diet

Title Search Strategy                    obesity [ti] exercise [ti] diet [ti]

                                                          obesity [ti] diet [ti]

                                                           obesity [ti] exercise [ti]

Synonym Strategy                         overweight [ti] aerobic  [ti]

                                                           overweight [ti] diet [ti]


MeSH Search Strategy          obestity [mh] AND diet [ti] AND exercise [ti]

                                       overweight [mh] AND diet [ti] AND exercise [ti]