BACKGROUND Phase II cancer studies are undertaken to assess the activity of a new drug or a new treatment regimen. Activity is sometimes defined in terms of a survival probability, a binary outcome such as one-year survival that is derived from a time-to-event variable. Phase II studies are usually designed with an interim analysis so they can be stopped if early results are disappointing. Most...

Although using the 2-stage designs proposed in the literature has certain advantages such as limiting the expected number of people exposed to inactive agents while retaining overall size and power, the practical application of these methods can be challenging in a cooperative setting because of the difficulty in obtaining the exact sample sizes as demanded by these procedures. Chen and Ng prop...

Background Antiphospholipid syndrome is characterized from venous, arterial and small vessels thromboembolic events leading to significant morbidity mortality despite current treatments. Albeit, the acute diseases manifestations of antiphospholipid are well known, data on damage accrual still lacking. Objectives To assess frequency in (APS) evaluate association with different laboratory clinica...

* Marc Robinson is a European-based international consultant and trainer. This article was written when he was a senior economist in the Fiscal Affairs Department of the International Monetary Fund. The author gratefully acknowledges the valuable comments of Marco Cangiano, Ian Lienert, Gösta Ljungman, David Fjord Nielsen, Eivind Tandberg and participants in a seminar in the Fiscal Affairs Depa...

Failure detectors are one of the fundamental components for building a distributed system with high availability. In order to maintain the efficiency and scalability of failure detection in a complicated large-scale distributed system, accrual failure detectors that can adapt to multiple applications have been studied extensively. In this paper, an new accrual failure detector--LA-FD with low s...