Systematic Reviews: Inclusion and Exclusion Criteria
Defining Inclusion/Exclusion Criteria
An important part of the SR process is defining what will and will not be included in your review.
Inclusion and exclusion criteria are developed after a research question is finalized but before a search is carried out. They determine the limits for the evidence synthesis and are typically reported in the methods section of the publication. For unfamiliar or unclear concepts, a definition may be necessary to adequately describe the criterion for readers.
Some examples of common inclusion/exclusion criteria might be:
- Date of publication: only articles published in the last ten years
- Exposure to intervention/ or specific health condition: only people who have participated in the DASH diet
- Language of Publication*: only looking at English articles
- Settings: Hospitals, nursing homes, schools
- Geography: specific locations such as states, countries, or specific populations
*note of caution: research is published all over the world and in multiple languages. Limiting to just English can be considered a bias to your research.
What happens if no study meets my inclusion/exclusion criteria?
Empty reviews are when no studies meet the inclusion criteria for a SR. Empty reviews are more likely to subject to publication bias, however, they are important in identifying gaps in the literature.
- Unanswered questions implications of an empty reviewSlyer, Jason T. Unanswered questions, JBI Database of Systematic Reviews and Implementation Reports: June 2016 - Volume 14 - Issue 6 - p 1-2 doi: 10.11124/JBISRIR-2016-002934
- Rapid Prompting Method and Autism Spectrum Disorder: Systematic Review Exposes Lack of EvidenceSchlosser, R.W., Hemsley, B., Shane, H. et al. Rapid Prompting Method and Autism Spectrum Disorder: Systematic Review Exposes Lack of Evidence. Rev J Autism Dev Disord 6, 403–412 (2019).