Minimization of regret has been adopted here as a decision making algo-rithm in order to select the best medicine from a collection of drugs considered in the treatment of an individual patient. We assume that symp-toms affected by medicines have a compound qualitative complexion. A model of evaluating the effectiveness of drugs, exerting an influence on qualitative features, is employed to found the utility matrix, which constitutes the input system in decision-making. We thus discuss the method that converts information obtained from a questionnaire to entries of the matrix mentioned. The last technique constitutes a main own contribution in evolving methods of fuzzy calculus.