Clinical trials : journal of the Society for Clinical Trials
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Background Bayesian statistics are an appealing alternative to the traditional frequentist approach to designing, analysing, and reporting of clinical trials, especially in rare diseases. Time-to-event endpoints are widely used in many medical fields. There are additional complexities to designing Bayesian survival trials which arise from the need to specify a model for the survival distribution. ⋯ Conclusion Few trials implemented a Bayesian survival analysis and few incorporated external data into priors. There is scope to improve the quality of reporting of Bayesian methods in survival trials. Extension of the Consolidated Standards of Reporting Trials statement for reporting Bayesian clinical trials is recommended.
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In settings like the Ebola epidemic, where proof-of-principle trials have provided evidence of efficacy but questions remain about the effectiveness of different possible modes of implementation, it may be useful to conduct trials that not only generate information about intervention effects but also themselves provide public health benefit. Cluster randomized trials are of particular value for infectious disease prevention research by virtue of their ability to capture both direct and indirect effects of intervention, the latter of which depends heavily on the nature of contact networks within and across clusters. By leveraging information about these networks-in particular the degree of connection across randomized units, which can be obtained at study baseline-we propose a novel class of connectivity-informed cluster trial designs that aim both to improve public health impact (speed of epidemic control) and to preserve the ability to detect intervention effects. ⋯ Incorporating information about cluster connectivity in the design of cluster randomized trials can increase their public health impact, especially in acute outbreak settings. Using this information helps control outbreaks-by minimizing the number of cross-cluster infections-with very modest cost in terms of power to detect effectiveness.
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Patients with cardiac arrest and other life-threatening emergencies are unable to provide prospective consent for clinical trials. In the United States and other countries, regulations permit an exception from the requirement for informed consent in emergency settings. However, many potential barriers exist, as evidenced by the scarcity of US trials conducted under exception from the requirement for informed consent. One persistent challenge is the requirement that investigators consult communities prior to study approval. ⋯ Exception from the requirement for informed consent regulations have advanced the goal of improving care for emergency conditions, but common interpretations of the community consultation requirement threaten research in the United States. Focusing on the goals of learning from and demonstrating respect for those most directly affected by a study through engaging people most connected to the condition of interest will make community consultation more valuable, better inform institutional review boards, and increase efficiency.
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Many clinical trial designs are impractical for community-based clinical intervention trials. Stepped wedge trial designs provide practical advantages, but few descriptions exist of their clinical implementational features, statistical design efficiencies, and limitations. ⋯ Stepped wedge trial designs that intervene in small clusters across longer periods can provide enhanced power to evaluate comparative effectiveness, while offering practical implementation advantages in geographic stratification, temporal change, use of existing data, and resource distribution. Current population estimates were used; however, models may not reflect actual event rates during the trial. In addition, temporal or spatial heterogeneity can bias treatment effect estimates.
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Participants in health research studies typically express interest in receiving the results from the studies in which they participate. However, participants' preferences and experiences related to receiving the results are not well understood. In general, the existing studies have had relatively small sample sizes and typically address specific and often sensitive issues within targeted populations. ⋯ We present findings from a survey assessing attitudes and experiences of a broad sample of respondents that addresses gaps in knowledge related to participants' preferences for receiving the results. The study's findings highlight the potential for inconsistency between respondents' expressed preferences to receive specific types of results via specific methods and researchers' unwillingness or inability to provide them. We present specific recommendations to shift the approach of new studies to investigate participants' preferences for receiving research results.