Background: previous studies had demonstrated the prevalence of illegitimate authorship, e.g. gift and ghost authors, despite the authorship guidelines established by the International Committee of Medical Journal Editors and implemented by Cochrane.

Objectives: this study aimed to estimate the prevalence of gift and ghost authors in Cochrane Reviews and to investigate possible predictors of inappropriate authorship.

Methods: we sent a web-based survey to first authors of Cochrane Reviews published between October 2016 and December 2018. The survey focused on the contribution of the first author and the co-authors of the specific Cochrane Review, and the authors’ general experience of following the authorship criteria in their academic work. The survey was conducted in REDCap, and the responses were anonymized prior to data extraction.

Results: data acquisition is ongoing and results will therefore be available for presentation at the Colloquium.

Conclusions: will be presented at the colloquium

Patient or healthcare consumer involvement: not relevant