A major trial needs three statisticians: why, how and who?

The statistical and scientific integrity of a major clinical trial is enhanced by having three distinct statistician roles: the Study Statistician, the Data Monitoring Committee (DMC) Statistician and the Independent Statistician. In any specific trial, careful attention should be given for selecting the right people to perform these tasks effectively. It is important that there are good communications amongst all three statisticians (and between each statistician and the other trialists) while preserving all confidentiality as regards interim results. Specifically regarding the Independent Statistician, it seems appropriate that they be truly independent having no other trial involvement than producing interim reports that inform the DMC (and be not employed by a commercial sponsor) but at the same time be fully aware of the trial protocol, objectives, organization and database.