Contemporary clinical trials
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Contemp Clin Trials · Mar 2009
Randomized Controlled Trial Multicenter Study Comparative StudyOperations and pelvic muscle training in the management of apical support loss (OPTIMAL) trial: design and methods.
The primary aims of this trial are: 1) to compare surgical outcomes following sacrospinous ligament fixation to uterosacral vaginal vault suspension in women undergoing vaginal surgery for apical or uterine pelvic organ prolapse and stress urinary incontinence and 2) to examine the effects of a structured perioperative program consisting of behavioral techniques and pelvic floor muscle training compared to usual care. This trial is performed through the Pelvic Floor Disorders Network (PFDN), which is funded by National Institute of Child Health and Human Development. Subjects will be enrolled from hospitals associated with seven PFDN clinical centers across the United States. ⋯ The primary surgical endpoint is a composite outcome defined by anatomic recurrence, recurrence of bothersome vaginal prolapse symptoms and/or retreatment and will be assessed 2 years after the index surgery. Endpoints for the behavioral intervention include both short-term (6-month) improvement in urinary symptoms and long-term (2-year) improvement in anatomic outcomes and prolapse symptoms. This article describes the rationale and design of this randomized trial, focusing on several key design features of potential interest to researchers in the field of female pelvic floor disorders and others conducting randomized surgical trials.
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Contemp Clin Trials · Mar 2009
Range and trend of expected toxicity level (ETL) in standard A + B designs: a report from the Children's Oncology Group.
The traditional algorithm-based 3+3 designs are most widely used for their practical simplicity in phase I clinical trials. At early stage, a common belief was that the expected toxicity level (ETL) at the maximum tolerated dose (MTD) should be 33% [Storer, B. Design and analysis of phase I clinical trials. ⋯ In this simulation study, we originally find that the ETL decreases monotonically from about 30% to 0% as the number of dose levels increase from 3 to infinity, which will correct the inaccuracy in the common belief among phase I trial investigators. To help better design and conduct phase I trials, we create a table as a reference for the association between ETL and number of dose levels considered in a design when the exact shape of the dose-toxicity relationship is not well understood. We conclude that the number of specified dose levels is an important factor affecting substantially the ETL at MTD and recommend that fewer than 20 dose levels be designated.