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Systematic Reviews

Developing an answerable question

The purpose of a systematic review is to summarize knowledge.  The review also creates new knowledge by providing a qualitative or quantitative synthesis.  By summarizing the available knowledge on a topic, the review can provide clarity if there is an abundance of information.  On the opposite end, it can demonstrate where there are gaps in the knowledge if there is too little information.  Another benefit of the review is providing a way to resolve discrepancies over a debated issue.

With the purpose of a systematic review in mind, this will help determine if your research question is appropriate for a systematic review.  Depending on the question, your time, and support structure, another review type may be a better fit.

A meeting with a librarian will be the best starting point for your project.  The Librarian can help you determine whether to move forward with a systematic review or another type.

"There are too many results."

Your research question should be tested in a database or two to see what results are being pulled.  If there are a lot of results, it is because the search strategy is not specific enough or does not adequately reflect the research question.  If the question is broad in scope, then you will retrieve a larger evidence base.  You can re-frame your question by adding in additional parameters, such as limiting to a particular care setting, limiting to a specific population age group, or adding in a comparison.  We recommend you work with a librarian to help focus your question, so you retrieve the amount of results you are comfortable working with for the review.

Types of review questions and examples
Effectiveness of a treatment, therapy, or policy

In patients with _____ (disease/condition), will _____ (treatment) be effective in treating the _____ (disease/condition)?

Harm Does doing _____ (activity) or being in _____ (location) increase incidence in _____ (disease/condition)?
Causation/risk factors What are the risk factors of doing ______ (activity) for _____ (population type)?
Screening or diagnosis
What is the best method to diagnosis _____ (disease/condition)?
What is the best method for screening _____ (disease/condition) in _____ (population type)?
Prognosis Are _____ (population type) more likely to have _____ (disease/condition)?
Prevention Will ____ (activity) prevent _____ (disease/condition) in _____ (population type)?
A person's experience or perceptive What are the experiences of people who _____ (activity)?
Service delivery Does _____ (activity) increase _____ (knowledge, satisfaction, efficacy) with _____ (population)?
Cost Effectiveness What are the most cost effective ways to _____ (activity) in _____ (location)?

Adapted from Jewell, S. T., & Foster, M. J. (2017). Assembling the pieces of a systematic review : a guide for librarians. Rowman & Littlefield.


A common framework for health related topics is PICO.  A question framework will help determine the main elements of a search, identify some keywords, set the basic search string structure, and provide detail on the objective.  By having a clear objective, you have the start of your eligibility criteria.

Letter Question to select search term
P: Patient, Population, or Problem How would I describe a group of patients similar to mine?
I: Intervention

Which main intervention, prognostic factor, or exposure am I considering?

C: Comparison or control What is the main alternative to compare with the intervention?
This could be to compare another treatment option or doing nothing.
O: Outcome What can I hope to accomplish, measure, improve, or affect?

Example PICO:  Does hand washing among healthcare workers reduce hospital acquired infections?

Problem: hospital acquired infection
Intervention: hand washing
Comparison: No hand washing; other solution, using face masks
Outcome: Reduced infection

Other Frameworks

The SPIDER question format was adapted from the PICO tool to search for qualitative and mixed-methods research.  Questions based on this format identify the following concepts:

Phenomenon of Interest
Research type

The WWH framework is an open, easy to use framework.  Most questions can fit into this framework.


The PICOT framework is similar to PICO, but adds in the element of time.  It is useful for questions relating to education or health care.


The PECODR framework is used for medical questions.


The PIPOH framework is used for screening related questions.

Healthcare setting

The BeHEMoTH framework is used for questions relating to theories.

Behavior of interest
Health context
Models or Theories

What if my topic doesn't fit into a framework?

Not every topic will fit neatly into a framework.  If this applies to you, then you can either only use the parts of a framework which do fit or don't use one at all.  The purpose of a framework is to separate your research question into different concepts.  It is important to identify the concepts so you know what to search.  Please reach out to a librarian if you need assistance identifying the main concepts of your question.

Working with a Librarian

As a team member, the librarian can frame the question, make the list of keywords/controlled vocabulary to search, build the search strings, and start a list of inclusion/exclusion criteria.

If the librarian is serving as an advisory role, assistance and education is provided on the following items.

Assistance for developing the research question

  • Assist in determining whether the question is appropriate for a systematic review or another review type
  • Assist in determining the scope of the review
  • Assist in starting a list of inclusion/exclusion criteria
  • Educate on common eligibility criteria items
  • Educate on identifying what article types to include in your review
  • Educate on locating other systematic reviews on your topic

Assistance for framing the question

  • Educate on using a framework
  • Assist in framing the question with PICO or another framework
  • Identify main topics that emerge from the framework
  • Assist in starting a list of keywords
  • Educate on locating additional keywords to use
  • Assist in starting the search structure/search string
  • Educate on searching logic (using AND, OR, NOT, wildcards, etc)