Randomized Clinical Trials, History, Designs. Questionable Use of Placebos and Questionable Lack of Placebos, and Stepped Wedge Designs
The last decades have witnessed a dramatic and welcome improvement in the methods of drug evaluation, and, therefore, our ability to use biological or pharmaceutical agents, which will benefit risk ratio, has been better assessed. While these changes have had an immense impact on the professional day to day lives of all those involved in human experimentation, there are still growing expectations for education information and reflections in a more demanding environment. This chapter will review the state of the art of clinical trials in the years 2015-2016, and will summarize for that purpose the statistics lectures given to the master ’s students of the European College of Pharmaceutical Medicine in Lyon France. The following subjects will be reviewed.
- 1. Randomized Controlled Trials (RCTs) are Highly Regulated
- 2. Clinical trial definition.
- 3. History.
- 4. Main use of clinical trials: causal inference.
- 5. Counterfactual assertion experiment.
- 6. Control in clinical trials by randomization.
- 7. Blinding and placebos.
- 8. Randomization methods.
- 9. Clinical trial classifications.
- 10. Experimental study designs.
Statistical methodologies are pretty complex to nonmathematicians. For improved understanding global medical publications will be used as examples, rather than hypothesized examples. We will also address pretty novel, but relevant subjects, like studies with questionable use of placebos, and those with questionable lack of placebos, and studies where blinding is impossible. Alternative forms of randomization will be reviewed, including minimisation, and biased coin
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randomization, as well as, adaptive randomizations. In addition to the traditional parallel group and crossover designs for trials, special study designs will be addressed, including dose-finding trials, cluster-randomized designs, sometimes called stepped wedge trials, and adaptive designs with umbrella-designs and basket- trials, as most recent alternatives. Web-based information for patients and professionals of ongoing and completed trials will be given attention as well.