The ideas proposed in this paper have been developed and tested using distributed databases containing information patients undergoing dialysis. The databases were residing at four different locations. They contained over 500 parameters for hundreds of patients, however the data was sparse. The data for some 50 different parameters (categorical, normative, and quantitative) was relatively complete.-The ideas proposed in this paper have been developed and tested using distributed databases containing information on patients undergoing dialysis. The databases were residing at four different locations. They contained over 500 parameters for hundreds of patients, however the data was sparse. The data for some 50 different parameters (categorical, normative, and quantitative) was relatively complete.