Contemporary clinical trials
-
Contemp Clin Trials · Jul 2009
Randomized Controlled Trial Comparative StudyRationale, design and baseline characteristics of the PRO-TECT II study: PROpofol CardioproTECTion for Type II diabetics: a randomized, controlled trial of high-dose propofol versus isoflurane preconditioning in patients undergoing on-pump coronary artery bypass graft surgery.
Diabetes mellitus is a leading cause of death globally and results in significant morbidity and mortality following surgery. After cardiac surgery, diabetic patients are especially at risk for low cardiac output syndrome, which can quadruple the risk for postoperative death. Attempts to prevent low cardiac output syndrome have focused on increasing myocardial tolerance to ischemia (preconditioning), which involves the myocardial mitochondrial ATP-regulated K(ATP) channel, G-protein initiation, nitric oxide synthase, and protein kinase C. ⋯ Effective antioxidant intervention during ischemia-reperfusion appears important for preserving myocardial function; thus, alleviating oxidant-mediated post-ischemic injury by increasing antioxidant defenses (cardioprotection) is an alternative to preconditioning. Our previous work suggests that propofol (2,6-diisopropylphenol), an intravenous anesthetic with antioxidant potential, may confer cardioprotection. In this paper, we describe the rationale and methodology of the Pro-TECT II Study, a Phase II randomized controlled trial designed to explore the relationships of biomarkers of oxidative or nitrosative stress in diabetes, to determine the effect of propofol cardioprotection to counteract these effects in patients undergoing elective primary coronary bypass graft surgery with cardiopulmonary bypass, and to provide feasibility and sample size data needed to conduct Phase III trials.
-
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.
-
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.
-
Contemp Clin Trials · Jan 2009
Randomized Controlled Trial Multicenter StudyPioglitazone versus vitamin E versus placebo for the treatment of non-diabetic patients with non-alcoholic steatohepatitis: PIVENS trial design.
Non-alcoholic steatohepatitis (NASH) is a common liver disease associated with obesity and diabetes. NASH is a progressive disorder that can lead to cirrhosis and liver failure. Insulin resistance and oxidative stress are thought to play important roles in its pathogenesis. There is no definitive treatment for NASH. ⋯ PIVENS enrollment started in January 2005 and ended in January 2007 with 247 patients randomized to receive either pioglitazone (30 mg q.d.), vitamin E (800 IU q.d.), or placebo for 96 weeks. Participants will be followed for an additional 24 weeks after stopping the treatment. The study protocol incorporates the use of several validated questionnaires and specimen banking. This protocol was approved by all participating center Institutional Review Boards (IRBs) and an independent Data and Safety Monitoring Board (DSMB) which was established for monitoring the accumulated interim data as the trial progresses to ensure patient safety and to review efficacy as well as the quality of data collection and overall study management. (ClinicalTrials.gov number, NCT00063622).
-
Contemp Clin Trials · Jan 2009
Randomized Controlled Trial Multicenter Study Comparative StudyThe Prostate cancer Intervention Versus Observation Trial:VA/NCI/AHRQ Cooperative Studies Program #407 (PIVOT): design and baseline results of a randomized controlled trial comparing radical prostatectomy to watchful waiting for men with clinically localized prostate cancer.
Prostate cancer is the most common noncutaneous malignancy and the second leading cause of cancer death in men. Ninety percent of men with prostate cancer are over aged 60 years, diagnosed by early detection with the prostate specific antigen (PSA) blood test and have disease believed confined to the prostate gland (clinically localized). Common treatments for clinically localized prostate cancer include watchful waiting surgery to remove the prostate gland (radical prostatectomy), external beam radiation therapy and interstitial radiation therapy (brachytherapy) and androgen deprivation. Little is known about the relative effectiveness and harms of treatments due to the paucity of randomized controlled trials. The VA/NCI/AHRQ Cooperative Studies Program Study #407: Prostate cancer Intervention Versus Observation Trial (PIVOT), initiated in 1994, is a multicenter randomized controlled trial comparing radical prostatectomy to watchful waiting in men with clinically localized prostate cancer. ⋯ PIVOT enrolled an ethnically diverse population representative of men diagnosed with prostate cancer in the United States. Results will yield important information regarding the relative effectiveness and harms of surgery compared to watchful waiting for men with predominately PSA detected clinically localized prostate cancer.