Systematic Reviews & Meta-analyses: Eligibility

Guidance on conducting systematic reviews and meta-analyses.


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Eligibility Criteria - What will determine which studies you include?

Overall - Your inclusion and eligibility criteria are a center feature of your protocol and 'a priori' design for your systematic review. These criteria guide which studies are selected for inclusion in your study during review steps: a. titles and abstracts; and b. full text review. 

These criteria should be guided by your research question and objectives, by the outcome measures that you will be considering to answer your question, including study design, methodology, and analysis methods that may impact the usefulness of including studies in your review in order to include the in your study overall and to include in your data analysis. Your context may also influence your criteria, such as the population of interest for your research question/objectives, particular geopgrahpic locations (United States, global, regional, local), particular settings (schools, urban or rural areas), and by other relevant contextual aspects of your research question and objectives. 

Example Inclusion criteria

  • Study population must be adolescents; or must include measures specifically of adolescent subgroup if population is a larger group (defined as between 12-19 years)
  • Study must have implemented a method for randomization
  • Study must be a controlled trial with a control and intervention group
  • Study must include a method for blinding
  • Study must have been conducted in an elementary school setting (equivalent to U.S. kindergarten through 6th grade)
  • Study must include outcome measures of BMI and body weight

Example Exclusion criteria - may be original, or may further clarify inclusion criteria

  • Exclude studies addressing combined school settings of combined elementary and middle school years with no subgroup analysis matching required group 
  • Exclude studies reporting only BMI or only body weight

Guidance and Examples for Developing Eligibility Criteria


Consider the guidance and requirements included in any overall guidelines that you're using, such as PRISMA, IOM, Cochrane, or other guidelines being used.

Additional Guidelines / Guidance

Cochrane Handbook, Chapter 2: Determining the Scope and the Questions it will address 
Editors: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA.

Key Points:
  • Systematic reviews should address answerable questions and fill important gaps in knowledge.
  • Developing good review questions takes time, expertise and engagement with intended users of the review.
  • Cochrane Reviews can focus on broad questions, or be more narrowly defined. There are advantages and disadvantages of each.
  • Logic models are a way of documenting how interventions, particularly complex interventions, are intended to ‘work’, and can be used to refine review questions and the broader scope of the review.
  • Using priority-setting exercises, involving relevant stakeholders, and ensuring that the review takes account of issues relating to equity can be strategies for ensuring that the scope and focus of reviews address the right questions.

2.1 Rationale for well-formulated questions

2.2 Aims of reviews of interventions

2.3 Defining the scope of a review question

2.3.1 Broad versus narrow reviews

2.3.2 'Lumping' versus 'splitting'

2.4 Ensuring the review addresses the right questions

2.4.1 Using priority-setting exercises to define review questions

2.4.2 Engaging stakeholders to help define the review questions

2.4.3 Considering issues relating to equity when defining review questions

2.5 Methods and tools for structuring the review

2.5.1 Logic models

2.5.2 Changing review questions 

2.5.3 Building in contingencies to deal with sparse data

2.5.4 Economic data

2.6 Chapter information

2.7 References