Spina bifida researchers believed that few women would participate if the surgery were available elsewhere, so they persuaded all but the three hospitals in the trial to stop doing the procedure, an unusual agreement.
This method was chosen to allow the trial to stop early for futility.
Especially for futility analyses, it is important to consider whether the trial can usefully contribute to an overview that could provide a definitive answer, but when the patient population is limited or there are no similar ongoing trials a decision to stop a trial in favour of standard treatment (or no treatment) can, in our view, be appropriate even when there is overall clinical uncertainty.
Five of the accused were on trial for failing to stop a massacre at the Ave Maria Church in Suai, in which at least 27 people, including three priests, were slain.
As a sequel to last week's paper on the fundamentals of clinical trial design, this paper tackles related controversial issues: noninferiority trials, the value of factorial designs, the importance and challenges of strategy trials, Data Monitoring Committees (including when to stop a trial early), and the role of adaptive designs.
Statistics should be considered as a tool, which could trigger the procedure to stop a trial but statistics cannot supplant a trial safety committee.
But in the contract the company can issue something called a gagging clause, which means it has the right to stop a trial early but still publish the results.
Like his Republican predecessor, the new attorney general, Eric Holder, happily invoked "state secrets" to stop a trial, while Obama's CIA boss (a former Clinton employee), Leon Panetta, was in feisty mood after he got the job, boasting that he fully intended to preserve "extraordinary rendition", that is, sending prisoners to be tortured in Afghanistan, Egypt, Jordan or Pakistan.
It briefly describes the statistical concepts behind sample size recalculation and interim analyses for efficacy and futility, with a brief discussion on when to stop a trial.
In practice, other outcomes (e.g., safety) will also be monitored and influence the decision whether to stop a trial early.
