Application of intuitionistic fuzzy sets for more objective comparison of Kaplan-Meier curves

In the present work a scheme for more objective comparison of patients, represented by Kaplan-Meier graphs, by classification separating them in groups (m in number) with "graded survivability" is proposed. The classification uses the apparatus of the intuitionistic fuzzy sets (IFS). The final result is a clear and easy to interpret table. To avoid loss of information, as well as for the obtainment of graded, sound and real evaluation of the information, contained in the Kaplan-Meier graphs the authors recommend the consideration of all possible cases, for which it is fulfilled n<;m, where n is the number of the patient groups, represented by Kaplan-Meier survivability curves. A particular case from the neurosurgical practice is considered and analyzed. The obtained results are confirmed in practice and in the scientific literature.