Decision analysis: Theory and methods in clinical development and monitoring of clinical trials

Decision analysis has been widely used in business, first in operational research, later in economic studies. It is now spreading to medical training. We review methodology of decision analysis which is simple, rational and based on the environmental conditions. When clinical judgments are uncertain, the most appropriate strategy is helped by the use of standard/bayesian probabilities quantifying the risks of each strategy, and the design of decision trees visualizing each outcome. If the probabilities are not suitable, other mathematical concepts such as Markov process are interesting but are still being worked on. Multicriteria analysis, a branch of graph theory, is also a flexible and reliable tool allowing differentiation and ordering strategies. It also takes into account the psychological characteristic of the decision makers. We then illustrate decision analysis by describing computerized systems for monitoring clinical trials, fitted to control the trial data able to estimate the different strategies.