Controlled clinical trials
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Control Clin Trials · Dec 2004
ReviewMeasuring treatment impact: a review of patient-reported outcomes and other efficacy endpoints in approved product labels.
The term "patient-reported outcomes" (PROs) has evolved to include any endpoint derived from patient reports, whether collected in the clinic, in a diary, or by other means, including single-item outcome measures, event logs, symptom reports, formal instruments to measure health-related quality of life (HRQL), health status, adherence, and satisfaction with treatment. This term coincides with the explicit interest from drug development researchers and regulatory authorities in the appropriate utilization and reporting of treatment impact measures. ⋯ PROs, although quite variable as a class of study endpoints, were found to have a significant role in the development and evaluation of new medicines. More formal guidance from the FDA about use of such measures along with continued collaboration by PRO researchers to develop and disseminate standards will enhance the appropriate use of PROs in future drug development and labeling.
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Control Clin Trials · Dec 2004
ReviewAn analysis of the effect of funding source in randomized clinical trials of second generation antipsychotics for the treatment of schizophrenia.
The effect of funding source on the outcome of randomized controlled trials has been investigated in several medical disciplines; however, psychiatry has been largely excluded from such analyses. In this article, randomized controlled trials of second generation antipsychotics in schizophrenia are reviewed and analyzed with respect to funding source (industry vs. non-industry funding). ⋯ While the retrospective design of the study limits the strength of the findings, the data suggest that industry bias may occur in randomized controlled trials in schizophrenia. There appears to be several sources by which bias may enter clinical research, including trial design, control of data analysis and multiplicity/redundancy of trials.
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Control Clin Trials · Dec 2004
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialSymptom recording in a randomised clinical trial: paper diaries vs. electronic or telephone data capture.
Patients may be asked to register a symptom daily in clinical trials. A problem associated with this kind of registration is that patients do not always fill in the diary at the appropriate time. As there is evidence showing that memory is unreliable, this undermines the entire purpose of collecting daily data on paper diaries. We aimed to compare accuracy, autocorrelations of consecutive entries, and responsiveness in paper diaries (P-Diaries) with electronic diaries (E-Diaries) and telephone diaries (T-Diaries). ⋯ The results are consistent with the suggestion that data in the P-Diaries are not filled in at the appropriate time. Use of E-Diaries or T-Diaries improves quality and is recommended in future clinical trials.
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Control Clin Trials · Oct 2004
The utility of partial cross-over designs in early phase randomized prevention trials.
In this note, we outline the benefits of a partial cross-over design for a class of experiments where the interest is the cumulative effect of dose versus placebo. The goal of our design strategy is to answer several complex question efficiently in a phase II setting with a minimal number of assumptions with an eye towards planning a phase III study.
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Control Clin Trials · Dec 2003
Randomized Controlled Trial Clinical TrialAn international multicenter protocol to assess the single and combined benefits of antiemetic interventions in a controlled clinical trial of a 2x2x2x2x2x2 factorial design (IMPACT).
For various diseases clinicians have to combine different drugs or interventions when a single drug or intervention does not lead to satisfactory results. However, quantifying the relative benefit of certain drugs or interventions when given alone and in combination under controlled conditions requires a complex factorial design. This paper describes such a method applied to a large multicenter trial for the prevention of postoperative nausea and vomiting (PONV), which may be of great interest for other specialties. ⋯ Eligible patients are adults scheduled for elective surgery under general anesthesia with an increased risk for PONV so that the expected incidence in the control group (with none of the six antiemetic interventions) is approximately 60%. In order to allow analyses for up to three factor interactions, a sample size was estimated to be in the range of approximately 5000 patients. To the best of our knowledge this is the first randomized controlled trial of a six-way factorial design that may serve as an example for numerous other medical specialties.