Challenges and considerations in assessing the reporting quality of systematic reviews in overviews using PRISMA

Article type
Authors
Jia P1, Chen J2, Zhang L1, Zhao P1, Zhang M1
1Chinese Cochrane Center, China
2West China Hospital, China
Abstract
Background: Overviews bring systematic reviews (SRs) together and serve as a user-friendly 'digest' that can be used by clinicians and policy makers in making decisions. Poor reporting of SRs diminishes value of the overview to clinicians and policy makers. The reporting quality of SRs can be evaluated using the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analysis) system.
Objectives: To evaluate the reporting quality of SRs involved in overviews; to examine the difference exiting PRISMA scores make across Cochrane and non-Cochrane SRs.
Methods: We randomly selected eight overviews and searched all the SRs included in the overviews. Each PRISMA item is given a score of 1 if the criterion is met, a score of 0.5 if the criterion is partially met, or a score of 0 if the criterion is not met, or not applicable. Two reviewers independently evaluated the quality of included SRs and discrepancies were solved by consensus.
Results: Ninety-eight SRs were included; 28 of these were published in 2009. The 98 SRs were from four major areas: cancer, hypertension, skin and stroke. Among the 98 SRs, 36 SRs were Cochrane SRs. The total PRISMA scores were (22.5 ± 10.2). Average Cochrane scores (25.5 ± 11.7) were much higher than the non-Cochrane reviews (20.5 ± 13.5). The reporting quality varied in both Cochrane and non-Cochrane reviews: several items were strong, including reporting of data collection process (100%), selection of articles (100%) and synthesis of results (100%). In some items, the reporting quality of Cochrane SRs was better than the non-Cochrane SRs, such as: protocol and registration and reporting of search strategies.
Conclusions: The reporting quality of Cochrane SRs was higher than that of non-Cochrane SRs.The missing information in the Cochrane and non-Cochrane SRs may influence the use of overviews, so the reporting quality in the Cochrane and non-Cochrane SRs needs to be improved.