Overviews of reviews in the cardiovascular field underreported critical methodological and transparency characteristics: a methodological study based on the Preferred Reporting Items for Overviews of Reviews (PRIOR) statement

This study aimed to evaluate the epidemiology, reporting characteristics, and adherence to the Preferred Reporting Items for Overviews of Reviews (PRIOR) statement of overviews of reviews (overviews) of interventions in the cardiovascular field. MEDLINE, Scopus, and the Cochrane Database of Systematic Reviews were searched from January 1, 2000, to October 15, 2020. An updated search was performed in MEDLINE, Epistemonikos, and Google Scholar up to August 25, 2022. Overviews of interventions published in English and primarily considering populations, interventions, and outcomes pertinent to the cardiovascular field were eligible. Study selection, data extraction, and PRIOR adherence assessment were performed by two authors independently. We analyzed 96 overviews. Almost half (43/96 [45%]) were published between 2020 and 2022 and contained a median of 15 systematic reviews (SRs) (interquartile range, 9–28). The commonest title terminology was “overview of (systematic) reviews” (38/96 [40%]). Methods for handling SR overlap were reported in 24/96 (25%), methods for assessing primary study overlap in 18/96 (19%), handling of discrepant data in 11/96 (11%), and methods for methodological quality or risk of bias assessment of the primary studies within SRs in 23/96 (24%). Authors included data sharing statements in 28/96 (29%), complete funding disclosure in 43/96 (45%), protocol registration in 43/96 (45%), and conflict of interest statement in 82/96 (85%) overviews. Insufficient reporting was identified in methodological characteristics unique in overviews' conduct and most transparency markers. Adoption of PRIOR from the research community could ameliorate overviews’ reporting.