Trial registration 10 years on

This month marks the tenth anniversary of the landmark decision by the International Committee of Medical Journal Editors to make journals require “registration of any clinical trials in a public trials registry at or before the time of first patient enrolment as a condition of consideration for publication.”1

It has been a long journey. The idea of prospective registration was first suggested in 1986,2 but it took two decades for the idea to become reality. Since then both the United States and the European Union have passed legislation making registration a legal requirement for most types of clinical trials. Accordingly, the number of registered trials has gone up dramatically—ClinicalTrials.gov currently lists 189 473 studies, the EU register has 25 829, and the Chinese Clinical Trial Registry has 5199.3

As medical journal editors we are convinced that the requirement for prospective trial registration is the single most valuable tool we have to ensure unbiased reporting. It allows us to make sure …