Some thoughts on the implementation of a mass screening process

Screening consists in identifying subjects at highrisk for an illness or who present an infra-clinical form of a disease in order to prevent its appearance or further development. A screening procedure which does not offer a proven benefit for the individuals in the target population is not justified and makes no sense. Screening for a risk or for a disease has become an important stake in our society and therefore requires that we carefully consider the type and validity of the scientific data forming the basis of a given screening procedure. In addition to merely assessing the scientific aspects, we also have to carefully consider the practical constraints of the screening procedure for individuals confronted with the procedure itself and its consequences as well as the implications for society in general in financial and structural terms. The practical aspects should insure that the individuals who can obtain the most benefit be readily and precisely identified and that the screening procedure selected undergo appropriate scientific evaluation. In this article, the scientific council of the CNAMTS wishes to share its personal experience and some of its thoughts based on the study of patient files. After outlining a few conceptual notions concerning screening in general, the authors turn their attention to a number of specific details of screening procedures, the associated intervention and parameters which can be used for evaluating its efficacy in addition to possible alternative strategies. Finally, they present a list of benchmarks which can be helpful for drafting an evaluation protocol for screening procedures.