It is a best practice expectation that all research should be registered in a publicly accessible database. However, for clinical trials, it is a condition of a favourable ethical opinion to do so. Since September 2013, the registration of clinical trials has been a formal condition of NHS Research Ethics Committee (REC) approval, in line with researcher and sponsor duties as set out by the WHO, current Declaration of Helsinki and the Research Governance Framework. EU legislation also requires that clinical trials of investigational medicinal products (CTIMPs) are entered in a public register (with limited exemptions for healthy volunteer studies). Registration should occur before the first participant is recruited. 

The International Committee of Medical Journal Editors (ICMJE) considers clinical trials for publication only if registered in an appropriate registry.

Any study that is registered on a public database must report its results on that databse within one year of study completion (or six months for paediatric studies). 

Clinical trial registration and results reporting helps to prevent selective publication and selective reporting of research outcomes, to prevent unnecessary duplication of research effort, and to help patients and the public know what trials are planned or ongoing.

Clinical trials are defined as all studies which fall into the first four categories of question two on the Integrated Research Approval System (IRAS) filter page. These are:
     • Clinical trial of an investigational medicinal product
     • Clinical investigation or other study of a medical device
     • Combined trial of an investigational medicinal product and an Investigational medical device
     • Other clinical trial to study a novel intervention or randomised clinical trial to compare interventions in clinical practice.

A ‘public registry’ is defined as any register on the WHO list of primary registries or the ICMJE list of registries. Examples include:

Please contact the Research Integrity Officer if you have any queries about registering a study or reporting results. For further information please see SOP 022 on adding study details to public databases.