[A network of epidemiological information in community medicine practice: methodological principles of the VENUS Program].

Implementation of epidemiological studies involving the participation of large networks of ambulatory care physicians requires prior resolution of the methodological dilemma between a "volunteer sentinel doctors" approach and one based on sampling techniques. A study of the VENUS program (concerning Sexually Transmitted Diseases) illustrates this latter approach for which formulae are proposed for estimating the rate of incidence in the population. Methodological implications of this technique are commented upon, and the complementary indications for the two techniques for gathering information on ambulatory morbidity are discussed.