Search strategies in Campbell reviews are generally good but grey literature searching and some standards need to be better reported.
The review in brief
Campbell Collaboration systematic reviews search a wide range of sources and grey literature and, in most cases, report detailed database searches and a complete list of sources. While search methods are generally good, there are some reporting standards that are often not met, possibly impacting the transparency and reproducibility of the review. Increased use of Campbell search guidance documents, the development of additional support for Campbell authors related to searching, and encouraging co-author level involvement of information specialists may help improve conduct and reporting of searches in Campbell reviews.
What is this review about?
Campbell Collaboration systematic reviews aim to bring together knowledge from published and unpublished research to inform policy and decision-making. Searching for studies is a key step in conducting a high quality review of the literature. Until now, no in-depth assessment of the methods used for searching in Campbell Collaboration systematic reviews had been performed.
What is the aim of this review?
The current practices used by Campbell systematic review authors to conduct and describe their search methods for finding studies for their review were assessed. We wanted to know if Campbell review authors adhere to current standards and best practices for searching for systematic reviews and identify areas for improvement.
What studies are included?
We included Campbell systematic reviews published from 2017 until March 2024, which reported an original search strategy written in 2017 or later.
What are the main findings of this review?
In general, Campbell systematic reviews conduct broad searches in a wide range of databases and grey literature. Search strategies for databases were reported in most reviews, and show good practices related to the conduct of searches. There were some reporting standards that were less frequently met, such as reporting of grey literature searches, website URLs and database date ranges, impacting the reproducibility of searches. When information specialists are co-authors, adherence to standards and quality improves for some search characteristics. There is also a time lag of about 20 months on average between the most recent search and the publication date.
What do the findings of this review mean?
While most Campbell systematic reviews conduct good quality searches across a wide range of databases and grey literature sources, there are some conduct and reporting standards that are not fully met by all reviews. These findings can help identify opportunities for improving current practices in Campbell reviews through updated guidance, peer review processes and author training and support.
How up-to-date is this review?
This review included all the Campbell systematic reviews published between January 2017 and March 2024.