Study highlights inadequate data monitoring in clinical trials

In a recently published research article in Trials, Dr Floriani and colleagues assess the prevalence of interim analyses in 150 cancer randomized controlled trials and conclude that there is still insufficient attention paid to the implementation of this statistical approach for data monitoring.

Interim analyses are known to play an important role in balancing between the need for timely information regarding the treatment effect, the control of false positive errors and estimation bias. To evaluate the current practice of planned monitoring for protocols with ongoing patient recruitment, the authors of this study extracted data from protocols of cancer clinical trials included in the Italian registry of clinical trials from 2000 to 2005.

Despite the opportunity to repeatedly evaluate data in trials of chronic diseases, the study finds that 30% of the protocols do not incorporate any interim analysis plan and only 56% of protocols can be considered adequately planned for monitoring the trial.  These findings may be useful for improving organization and conduction of clinical trials that may be at risk of being terminated early unnecessarily. 


to interim analysis of cancer randomised clinical trials with time to
event endpoints: a survey from the Italian National Monitoring Centre
for Clinical Trials

Irene Floriani, Nicole Rotmensz, Elena Albertazzi, Valter Torri, Marisa De Rosa, Carlo Tomino, Filippo de Braud
Trials 2008, 9:46 (25 July 2008)
[Abstract] [Provisional PDF]

Trials is dedicated to investigating any aspect of the design, performance, and findings of randomized controlled trials.  The journal is overseen by Doug Altman (United Kingdom), Curt Furberg (United States), Jeremy Grimshaw (Canada) and Peter Rothwell (United Kingdom), the Editors-in-Chief, and an expert editorial board. If you would like more information on the journal, please contact the editorial office.

Abigail Jones
Assistant Editor – Trials

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