Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

To minimise bias, clinical trials must be randomised, and all patients analysed by allocated treatment. With several separate randomisations, patients should be analysed only within the randomisation they entered, and not compared against patients in different randomisations. Some people worry that randomised trials result in many patients receiving an inferior treatment. Accordingly, several suggestions have been made, including a combined control arm for many trials, and performing several randomisations at the same up-front time point. These approaches fundamentally contradict the above statistical principles, and can lead to wrong conclusions. We explore these problems, with reference to one such recent proposal.

Type

Journal article

Journal

Leuk Res

Publication Date

12/2003

Volume

27

Pages

1071 - 1073

Keywords

Bias, Data Collection, Humans, Neoplasms, Randomized Controlled Trials as Topic