ERIC Number: EJ1253712
Record Type: Journal
Publication Date: 2020-Jan
Pages: 12
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-1759-2879
EISSN: N/A
Available Date: N/A
Examining Overlap of Included Studies in Meta-Reviews: Guidance for Using the Corrected Covered Area Index
Hennessy, Emily A.; Johnson, Blair T.
Research Synthesis Methods, v11 n1 p134-145 Jan 2020
Overlap in meta-reviews results from the use of multiple identical primary studies in similar reviews. It is an important area for research synthesists because overlap indicates the degree to which reviews address the same or different literatures of primary research. Current guidelines to address overlap suggest that assessing and documenting the degree of overlap in primary studies, calculated via the "corrected covered area" (CCA) is a promising method. Yet, the CCA is a simple percentage of overlap and current guidelines do not detail ways that reviewers can use the CCA as a diagnostic tool while also comprehensively incorporating these findings into their conclusions. Furthermore, we maintain that meta-review teams must address non-independence via overlap more thoroughly than by simply estimating and reporting the CCA. Instead, we recommend and elaborate five steps to take when examining overlap, illustrating these steps through the use of an empirical example of primary study overlap in a recently conducted meta-review. This work helps to show that overlap of primary studies included in a meta-review is not necessarily a bias but often can be a benefit. We also highlight further areas of caution in this task and potential for the development of new tools to address non-independence issues.
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Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Audience: N/A
Language: English
Sponsor: National Institutes of Health (DHHS)
Authoring Institution: N/A
Grant or Contract Numbers: 5U24AG052175
Author Affiliations: N/A