Clinical trials : journal of the Society for Clinical Trials
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Randomized Controlled Trial Multicenter Study Comparative Study
DISPACT trial: a randomized controlled trial to compare two different surgical techniques of DIStal PAnCreaTectomy - study rationale and design.
Surgery is of increasing importance in the treatment and outcome of diseases of the pancreas worldwide. The incidence of pancreatic cancer (7-11/ 100,000 per year) has risen over the last years and surgical resection remains the only option for definite cure. Twenty-five percent of all resections are left of the superior mesenteric vein (distal pancreatectomy) and the appropriate closure technique for the pancreatic remnant remains unclear. Pancreatic fistulas are the most common (0-40%) and relevant postoperative complication. The optimal surgical strategy for pancreatic resection needs to be identified from the large number of surgical procedures available today. ⋯ A group-sequential study design accounts for the uncertainty of pre-existing evidence. Also, standardization of surgical and postoperative care and blinded outcome assessment as well as adjustment for varying surgical expertise will contribute to a high validity and generalizability of the results.
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A meta-analysis of randomized controlled trials suggested that rosiglitazone, a drug used for the treatment of diabetes, may be associated with an increased risk of cardiovascular adverse events. Three large randomized trials, designed specifically to address cardiovascular outcomes of rosiglitazone treatment, have published new or updated results. ⋯ Rosiglitazone appears to be associated with an increased risk of myocardial infarction and heart failure, but not death due to cardiovascular causes. When a meta-analysis of rare events is contemplated, a thorough sensitivity analysis using different methods to combine studies and an evaluation of different continuity corrections should be undertaken. When possible, an individual patient data meta-analysis should be performed, allowing time-to-event analysis and the identification of patient subgroups at an increased risk of adverse outcomes.
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Qualitative checklists for phase III trials have been proposed, to improve the reporting of such trials and to assess the validity of their results. ⋯ A quality assessment checklist was developed for improved critical appraisal of the reporting of cytotoxic, dose-finding phase I oncology trials. This may be a first step toward a minimum standard of quality measures for all phase I clinical trial reports.
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Comparative Study
A comprehensive comparison of the continual reassessment method to the standard 3 + 3 dose escalation scheme in Phase I dose-finding studies.
An extensive literature has covered the statistical properties of the Continual Reassessment Method (CRM) and the modifications of this method. While there are some applications of CRM designs in recent Phase I trials, the standard method (SM) of escalating doses after three patients with an option for an additional three patients SM remains very popular, mainly due to its simplicity. From a practical perspective, clinicians are interested in designs that can estimate the MTD using fewer patients for a fixed number of doses, or can test more dose levels for a given sample size. ⋯ We show that CRM-based methods are an improvement over the SM in terms of accuracy and optimal dose allocation in almost all cases, except when the true dose is among the lower levels.
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In non-cancer phase II trials, dose-finding trials are usually carried out using fixed designs, in which several doses including a placebo are randomly distributed to patients. However, in certain vulnerable populations, such as neonates or infants, there is an heightened requirement for safety, precluding randomization. ⋯ In phase II dose-finding studies in which failure targets are below 20%, the CRM appears quite sensitive to first unexpected outcomes. Using a power model for dose-response improves some behavior if the trial is started at the first dose level and includes at least three to five patients at the starting dose before applying the CRM allocation rule.