[Primary prevention trial. Methodological problems].

Abstract

Primary prevention trials are the best method of demonstrating the true value of medical intervention to correct abnormalities of lipid metabolism. A large number of patients must be followed up for a long period and this explains the complexity of the logistic problems which are encountered. However, these trials must conform to the classical guide lines of all clinical trials: an accurate definition of the study population, a principal criterion of adjustment which satisfies the golden rule "One question, one study".