Stopping rules for clinical trials incorporating clinical opinion

A method is described of eliciting a 'range of equivalence', i.e. a range of differences between two treatments over which a group of clinical trial participants would have no clear preference for either treatment. This range of equivalence is then incorporated into a formal stopping rule for the trial using an extension of the group sequential design. Tables for the implementation of the design are presented. The method is discussed in the context of other sequential-trial designs.     

Advances in clinical research methodology for pain clinical trials

Pain is a ubiquitous phenomenon, but the experience of pain varies considerably from person to person. Advances in understanding of the growing number of pathophysiologic mechanisms that underlie the generation of pain and the influence of the brain on the experience of pain led to the investigation of numerous compounds for treating pain. Improved knowledge of the subjective nature of pain, the variations in the measurement of pain, the mind-body placebo effect and the impact of differences in the conduct of a clinical trial on the outcome have changed approaches to design and implement studies. Careful consideration of how these concepts affect the choice of study population, the randomization and blinding process, the measurement and collection of data, and the analysis and interpretation of results should improve the quality of clinical trials for potential pain therapies.     

Developing clinical guidelines

The methods of guideline development should ensure that treating patients according to guidelines will achieve the outcomes that are desired. This article presents a combination of the literature about guideline development and the results of our combined experience in guideline development in North America and Britain. It considers the 5 steps in the initial development of an evidence-based guideline.