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Searching the Literature for Evidence-Based Answers: Acquire


  • Review what the question is trying to find to determine the study type that will give the best evidence.
  • Use the best resource available that will provide answers that are backed up by evidence.
  • Use the keywords and clinical question to focus your search for answers.

Question Types

Once you have created the clinical query, you have to look at what kind of question you have. Clinical queries are asked for a purpose. These questions are looking to find evidence to guide a health professional to a decision regarding a situation. In some cases, the question is trying to find the best treatment or therapy. In other cases, the question may be searching for a long prognosis, or the best diagnostic tool to use. There are a number of different question types that may be asked.

Understanding what type of question is being  researched is important for two main reasons. The first is that each question type can be answered more usefully by specific article types. The second reason is that you can use the question type as a term to help narrow down the list of results found when performing a literature search. For example, in searching most health databases, the term “prognosis” can be added as a part of a search to narrow down the results.

For researchers with strong biostatistics skills, any specific research article types can be analyzed to ensure the evidence provided is accurate and fits the needs of the clinical situation. 

Some of the typical questions types include:

  • Therapy/Treatment – These questions look to determine best ways to fix problems
  • Diagnosis – These questions look to find the best way to find out if there is a problem, or which problem it might be
  • Etiology/Harm – These questions look at what may be causing the problem
  • Prognosis – These questions look at long term outlooks due to the problem

Keep in mind that systematic reviews, critically-appraised topics and meta-analyses are also good article types if the topic is well-researched.

Searching the literature

Take all the terms you have found from asking your background questions and use them to fill in your PICO. Then use your PICO terms to search the literature.

Remember when searching, that some terms such as female and child, can be used to refine the results of a search. Also, consider using alternate forms of the terms such as pediatric instead of child. 

To further refine the results, you can also add the question type such as "therapy" or "prognosis" as a term. Additionally, you could try using the study type such as "randomized control trial" or "cohort study" as a term, although many databases include this is as a refining option when performing a search.

Review your results to find the evidence that most closely matches your clinical situation.