Clinical trials : journal of the Society for Clinical Trials
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In clinical trials following individuals over a period of time, the same assessment may be made at a number of time points during the course of the trial. Our review of current practice for handling longitudinal data in Cochrane systematic reviews shows that the most frequently used approach is to ignore the correlation between repeated observations and to conduct separate meta-analyses at each of a number of time points. ⋯ It is preferable to obtain IPD from all studies to correctly account for the correlation between repeated observations. When IPD are not available, the ideal aggregate data are model-based estimates of treatment difference and their variance and covariance estimates. If covariance estimates are not available, sensitivity analyses should be undertaken to investigate the robustness of the results to different amounts of correlation.
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Solid organ transplant recipients must take immune suppressive medications that have side effects, cause complications, and lead to distressing symptoms that reduce health-related quality of life (QOL). Mindfulness meditation has been shown to reduce these symptoms in other patient populations, and it is unlikely to interfere with the immune suppressive medication regimen. ⋯ The innovative design used in the trial enabled the waitlist group to directly contribute to the number in the primary analysis of active arms, and to also serve as an internal validation test. The trial may be a useful model for trials involving very small target populations.
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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.