A study or experiment can be described as sequential if its design includes one or more interim analyses at which it is possible to stop the study, having reached a definitive conclusion concerning the primary question of interest. The potential of the sequential study to terminate earlier than...

Adaptive seamless phase II/III clinical trial designs allowing treatment selection at an interim analysis have gained much attention because of their potential benefits compared to more conventional drug development programmes with separate trials for individual phases. A scenario of particular...

We develop semiparametric and parametric transformation models for estimation and comparison of ROC curves derived from measurements from two diagnostic tests on the same subjects. We assume the existence of transformed measurement scales, one for each test, on which the paired measurements have...

Often in sequential trials some additional data become available after a stopping boundary has been reached. A method for incorporating such information from overrunning is developed, based on a maximum-likelihood ordering of the sample space after overrunning. This yields a p-value for the...

We consider the following sequential testing problem. A group-sequential or fully-sequential test is carried out for a primary parameter, using a score process or an effective score process to eliminate nuisance parameters. After stopping, the possibility of additional parameters is considered,...

A receiver operating characteristic (ROC) curve is a plot of two survival functions, derived separately from the diseased and healthy samples. A special feature is that the ROC curve is invariant to any monotone transformation of the measurement scale. We propose and analyse semiparametric and...

We consider a semiparametric and a parametric transformation-to-normality model for bivariate data. After an unstructured or structured monotone transformation of the measurement scales, the measurements are assumed to have a bivariate normal distribution with correlation coefficient „ , here...