[Limitations of clinical trials]

The major limitation of randomized clinical trials is their restriction to interventions that are supposed to have a positive effect. Another limit is related to the difficulty to interpret or generalize the results because the studied population is very different from the population treated in normal life. Participating in a trial may also influence the results. Limitation also includes the specificity of the questions answered; the narrow perspective of many trials leaves aside important information related to the consequences of the intervention on quality of life, satisfaction or costs. Clinical trials usually do not provide the answers to the questions asked by practitioners and deciders. A solution consists in developing disease management approach which may include thousands of patients with the implementation of trials in real life with a long duration of follow-up.