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Systematic Review Resources: (P)IECES of a Systematic Review: Planning

This guide is designed to help you get started on a systematic review and provide guidance on a wide variety of resources.

What to consider when Getting Started

P: Planning

Time requires about 18 months of preparation “…to find out about a healthcare intervention it is worth searching research literature thoroughly to see if the answer is already known. This may require considerable work over many months…” (Cochrane Collaboration)

 The suggested timeline for a Cochrane review is: 

  • Preparation of protocol 1 – 2 months
  • Searches for published and unpublished studies 3-8 months
  • Pilot test of eligibility criteria 2-3 months
  • Inclusion assessments 3-8 months
  • Pilot test of ‘Risk of bias’ assessment 3 months
  • Validity assessments 3-10 months
  • Pilot test of data collection 3 months
  • Data collection 3-10 months
  • Data entry 3-10 months
  • Follow up of missing information 5-11 months
  • Analysis 8-10 months
  • Preparation of review report 1-11 months
  • Keeping the review up-to-date 12 months

Teamyou need to be working with: subject experts to help clarify issues related to the topic; librarians who can develop the comprehensive search strategies and identify the appropriate databases to search; reviewers who can screen abstracts and read the full text; statistician who can assist with the appropriate analysis of the data; and project leader who will coordinate and write the final report

Written protocol you need a written protocol that outlines the methodology, including the rationale for the systematic review, key questions broken into PICO components, inclusion/exclusion criteria, and literature search for both published and unpublished literature, data abstraction and data management, assessment of methodological quality of individual studies, data synthesis, and grading the evidence for each key question.

Registered protocolAfter you write the protocol, you should register it with PROSPERO, an International Prospective Register of Systematic Reviews. Registration is free and open to anyone undertaking systematic reviews of the effects of interventions and strategies to prevent, diagnose, treat, and monitor health conditions, for which there is a health related outcome. 

Literature searchingyou need to first identify systematic reviews that may already address the key questions; then identify the appropriate databases and conduct a comprehensive and detailed literature search that can be documented and duplicated; 

Citation management you need working knowledge of EndNote or other software package to help manage the citations from the literature search

Guidelines for reportingyou need to use the appropriate guideline for reporting your review for publication.

See I: Identifying under the UTHealth School of Public Health Library Systematic Review Resources : Steps of Review (PIECES ) Libguide

Why is it important to have a plan?

P: Protocol
A major cause of bias in a systematic review is answering a different question to that being originally asked. This is why it is important to develop a review plan or protocol to determine the inclusion and exclusion criteria you will use. Inclusion criteria is everything that a study must have in order to be included in your review. Exclusion criteria are the factors that would make a study ineligible to be included in your review. These criteria can include dates, how a study was designed, population, outcomes, etc.

The benefits of having a protocol before the beginning of a review:

  • relate to the validity and merit of a research process that reduces risk of bias
  • promotes a systematic rather than ad hoc approach to the review process
  • facilitates communication with others and promotes consistency between review team members support the reliability and usefulness of reviews to health professionals

​​The protocol should include:

  • Review question/objective
  • Inclusion/exclusion criteria (scope including types of studies, participants, interventions)
  • Search strategy
  • Methodology
  • Declaration of interests

It is recommended that you register your systematic review protocol prior to conducting your review. This will improve transparency and reproducibility, but will also ensure that other research teams do not duplicate efforts. If you are working with the Cochrane or Campbell Collaborations, you will publish your protocol with those organizations. If you are working independently, consider registration with:

PROSPERO: An international database of prospectively registered systematic reviews in health and social care. Key features from the review protocol are recorded and maintained as a permanent record.

See: The PLoS Medicine Editors (2011) Best Practice in Systematic Reviews: The Importance of Protocols and Registration. PLoS Med 8(2): e1001009. doi:10.1371/journal.pmed.1001009

Official Protocol Resources

Official Protocol Resources:

Inclusion/Exclusion Criteria

Inclusion/Exclusion Criteria: You need to identify the criteria that will be used to determine which research studies will be included. These inclusion and exclusion criteria must be decided before you start the review. This is to ensure that your search targets articles that will provide an answer to your review question, allowing you to exclude any irrelevant ones. Criteria that should be considered include:

Type of studies: It is important to select articles with an appropriate design for the research question.

Type of participantsIf focusing on a patient population, it is important to define their age, gender, diagnosis, as well as any other relevant factors.

Types of intervention: Describe the intervention that you are investigating. You may want to consider whether to include interventions carried out all over the world or just in the US. The Cochrane Collaboration recommends finding all available studies from all over the world. As before, the interventions that are to be excluded may also need to be described here.

Types of outcome measures: Outcome measures usually refer to measurable outcomes or ‘clinical changes in health’. For example, these could include body structures and functions like pain and fatigue, activities as in functional abilities and participation or quality of life questionnaires.

Developing a Targeted Question

I: Identifying 

Examine your topic to identify the major concepts you need to conduct the best searches.  Some useful ways to do this include:

  • Background planning: think of the 5 W's and H for your topic: 
    • Who - are the stakeholders, population of interest, involved parties 
    • What - are the issues, problems, needs
    • Where - are you, is the focus of the study / interest (single or multiple locations? small or large group?)
    • When - will researched changes be implemented, have related events or studies taken place
    • Why - is this problem, need, issue being addressed; why is your review study critical to addressing it
    • How - will possible solutions, interventions, other aspects of the research be assessed for effectiveness, quality; how will results be delivered and/or implemented


Focus-in by using the PICO(T) method to further develop one or more specific questions


What is PICO(T)

PICO is a tool commonly used in medical and health research to help researchers formulate a question. The difficulty in creating a question is often underestimated and PICO can help us parse out the important keys a good question should contain. This is just a tool, not a rigid structure in which all questions must fit.

P = Patient, Population, and/or Problem

I = Intervention

C = Comparison (not always applicable)

O = Outcome

T = *Type of Study (what study design is most appropriate to answer the question?)

Sometimes you will see PICO TT where the additional T stands for the type of question you are asking which you do need to know to determine the best study design. 

*In some PICO(T) models you will see T stand for time. This only works if your question includes a concept of time. 

      • PPopulation/Problem - what is the main problem you are addressing, what are the characteristics of related and/or stakeholder population/s, settings?
      • I: Intervention / method to Implement to address the problem of interest
      • C: any Comparison methods or interventions to research
      • OOutcome/s (measures reported in studies) of interest - what are measurable outcomes (standardized measures if possible) that would demonstrate the level of effectiveness of an intervention/implementation method or comparison that you are researching?
      • (T): (Time frame) - you may want to consider if there are specific time frames of interest for your research question and setting. In your context, is it important to review studies that have addressed the Problem / Population, Intervention/Implementation method, Comparison, and measured Outcomes within a specific period of time, such as 3 months; 1 year; an academic year; etc.
  • EXAMPLE – for the topic: Our group would like to research how/if socioeconomic factors leading to health disparities lead to a risk of late diagnosis of colorectal cancer. Our population of interest is people living in the United States, in Texas.  An intervention we’re considering implementing and studying to raise awareness and increase early diagnosis in order to improve successful treatment is to hold screening events and follow up with patient navigation techniques.
    • 5W’s and H:
      • Who: groups with socioeconomic factors leading to health disparities with a risk of late diagnosis of colorectal cancer
      • What: awareness and diagnosis of colorectal cancer
      • When: is there a time factor?  (for example if screening opportunities are available bimonthly, or some other time factor?
      • Where: in the United States, in TX
      • Why: to raise awareness of colorectal cancer and increase early diagnosis in order to improve likelihood of successful treatment
      • How: patient navigation and screening
    • PICO(T)
      • P: groups with socioeconomic factors leading to health disparities in the United States, inTX, with a risk of late diagnosis of colorectal cancer
      • I: Patient Navigation and screening
      • C: no comparison
      • O: raise awareness of colorectal cancer and increase early diagnosis in order to improve likelihood of successful treatment
      • (T): is there a time factor?  (for example if screening opportunities are available bimonthly, or some other time factor?)
  • Create a Research Question or PICO(T) Question from your major concepts – to help direct your search
    • Do Patient Navigation techniques (How/I) facilitate screening and early diagnosis of colorectal cancer (What/Why/O) for individuals with socioeconomic factors/health disparities in Texas, in the United States (Who//Where/P)?

After you have composed your research question, it's important to search if the question has been asked before. You will sometimes find that you may need to adjust your question based on the research found. See Searching for Prior Reviews.