Registry-based randomised controlled trials: conduct, advantages and challenges-a systematic review.

Optimising the design of rRCTs is dependent on the capabilities of the registry. New registries should be designed and existing registries reviewed to enable the conduct of rRCTs. At all times, data management and quality assurance of all registry data should be given key consideration. We suggest the inclusion of the term 'registry-based' in the title of all rRCT manuscripts and a clear simple breakdown of the registry-based conduct of the trial in the abstract to facilitate indexing in the major databases.