The article provides the findings of a complex socio-hygienic survey of the lifestyle and health status of 350 families of workers and employees of Izhevsk. The identified differences in the conditions and lifestyle of families with high and low rates of morbidity permitted to calculate the values of relative risk for the formation of pathology among family members. It made it possible on the basis of the theorem of hypotheses (the Bayes' formula) and the algorithm of sequential statistical procedures to develop a screening prognostic table for early identification of families with risk for frequent diseases and providing them with primary prevention measures that would contribute to the reduction of morbidity.