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Systematic Review

This guide aims to provide tools and resources that can be used for conducting a systematic review in medical and health sciences.

Resources on Formulating a Research Question

  • Cochrane Handbook for Systematic Reviews of Interventions version 6.2 - Chapter 2: Determining the scope of the review and the questions it will address from.
  • Cochrane Interactive Learning (a self-directed learning platform on the complete systematic review process.) - Module 1: Introduction to conducting systematic reviews. This module covers content about identifying the types of review questions and the elements of a well-defined review question.

Planning Research Questions

Defining the research question and developing a protocol are the essential first step in conducting systematic review. A well-formulated question will guide many aspects of the review process, including determining eligibility criteria, searching for studies, collecting data from included studies, structuring the syntheses, and presenting findings. 

PICO and Other Question Formation Frameworks

Question formation framework helps structure research questions. The PICO framework is commonly used to develop focused questions in academic and clinical settings. Other frameworks such as SPICE and SPIDER also serve the same purpose. Apart from structuring research questions, these frameworks also help:

  • establish scope of the review,
  • identify the key concepts in research questions, 
  • and organise the search terms for searching in library databases.

The PICO framework is widely used to develop focused clinical questions for quantitative systematic reviews. 

What does PICO stand for?

P Patients or Populations or Problems What is the patient's problem? What are the patient demographics such as age, gender and ethnicity? 
I Intervention What type of intervention is being considered? 
C Comparison or Control

Is there a comparison treatment to be considered? It can be another medication, another form of treatment, or no other treatment to compare.

O Outcome What is the desired effect or outcome from the intervention or treatment? 


SPICE can be used for both qualitative and quantitative studies with a focus on evaluating the outcomes of a service, a project, or an intervention.

What does SPICE stand for?

S Setting Where is the study being conducted (where)?
P Perspective

Who are the participants of the study (for whom)?

I Intervention What is the intervention being studied (what)?
C Comparison Compared with what other actions or outcomes (compared with what)?
E Evaluation

What is the result? How is it being measured (with what result)?


SPIDER is useful for qualitative or mixed methods research focusing on "samples" rather than populations.

What does SPIDER stand for?



Who is the group of people being studied?


Phenomenon of interest


What are the reasons for the behavior and decisions?



How has the research been collected (e.g., interview, survey)?


What is the outcome being impacted?

Research Type

What is the type of research (qualitative or mixed methods)?

Further Reading:

Cooke, A., Smith, D., & Booth, A. (2012). Beyond PICO: The SPIDER tool for qualitative evidence synthesis. Qualitative Health Research, 22(10), 1435-1443. 

How to turn a PICO question into a Search? (5.22 mins)

This video shows the way to turn a PICO question into a search in 5 steps.

Step 1: Identify the main elements of the question 

Step 2: Translate the question into the PICO framework

Step 3: Identify primary search terms from the PICO

Step 4: Think about the synonyms for the search terms

Step 5: Link up the synonyms and the PICO terms