Zombie reviews taking over the PROSPERO systematic review registry. It’s time to fight back!

Prospective public registration of medical research is an important step to decrease the risk of duplication and reduce research waste, and increase transparency.1 2 It is a requirement for funding and publication of most clinical trials. Systematic reviews (SRs) are also important medical research—compiling original research to answer a specific research question using systematic searches, pre-established selection criteria and critically appraising and synthesising evidence to help answer a clinical question—helping clinicians make the best possible clinical decisions. Unfortunately, this cohesive advance in science is under attack. This editorial aims to highlight the current status of prospective registration of SRs and provide five useful tips.  BJSM  publishes methodological tips and pearls for conducting SRs.3 The Centre for Reviews and Dissemination at the University of York hosts the international prospective registry platform for SRs, known as PROSPERO (https://www.crd.york.ac.uk/prospero/).4 The registry is free to use for both those registering reviews and those consulting the register. It is web-based and straightforward;,taking less than 1 hour to complete a registry entry once the author has gathered all the necessary information.5 Registering a SR involves navigating 22 mandatory and 18 optional fields that align with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.6 These fields cover the key methodological features of a SR that researchers need to consider for a good quality, clinically useful SR.7 A SR entry is only accepted for online registration after it has been evaluated by PROSPERO. The PROSPERO evaluation focuses on the completeness of the entry and its eligibility but does not include a consideration of the quality of the …