Previously, we accepted registrations provided the reviewers had not completed their data extraction but, from 1st October 2019, we will only accept reviews provided that data extraction has not yet started.
We hope that this will reduce the potential for bias by reducing the opportunity for data extraction to lead to conscious or subconscious effects on the review, for instance by influencing decisions to include or exclude certain items in order to shape a review so that it reaches a desired conclusion.
PROSPERO will continue to accept registrations if formal screening of search results against the review’s eligibility criteria is complete, because we understand that the steps of a review up to that point do not always follow a strictly sequential manner. We also recognise that registration before then may be challenging for reviews being done to a short timeline or strict deadline.
We continue to encourage authors to have written a full protocol before they register their review and to provide full and specific details on their methods in the PROSPERO registration record. Generic ‘cut and paste’ statements are discouraged.
Before completing a registration form, please check that your review is eligible for inclusion in PROSPERO