The boundary used depends on the number of interim analyses.

The Pocock boundary is simple to use in that the p-value threshold is the same at each interim analysis.

The results of this interim analysis were not revealed to the members of the study team until after the trial.

Data from the interim analysis of the Alpha trial of didanosine will be analysed early this year.

This trial was closed at interim analysis because of the lack of benefit from treatment with interferon.

Also noted that this trial was closed at interim analysis because of the lack of benefit from treatment with interferon.

Otherwise, it continues with periodic evaluations until a maximum number of interim analyses have been performed.

The study was unblinded early, at the very first interim analysis, due to the clearly emerging benefit of sunitinib.

If you were privy to the interim analysis, you would most likely choose the new drug over the placebo.

The design of many clinical trials includes some strategy for early stopping if an interim analysis reveals large differences between treatment groups.