ABSTRACT
An analysis of clinical data revealed a correlation between the relative frequency of joint appearance of changed signs and their functional relationship which is in contradiction to the value of the coefficient of stochastic link. Using an apparatus of the information theory the authors introduce a quantitative value of functional relationship between signs of the disease. A method is proposed of evaluation of the functional relationship between signs, the basis of which is calculation of the quantity of information contained in reports on the joint appearance of these signs in the disease. A formula was designed for calculating the coefficient of functional relationship. This method was approved on indices characterizing involvement of the pancreas in viral hepatitis.