关键词: 优势关系粗糙集, 可变精度粗糙集, 置信度, 支持数, 肾功能不全

Abstract: An extended rough set method is proposed with respect to decision problem of renal insufficiency diagnosis.This method combines dominance relation based rough set model with Variable Precision Rough Set（VPRS） model while confidence threshold of rule is regarded as the value of variable precision parameter.Firstly，criteria is discretized.Then，decision table is processed according to confidence threshold and support number threshold of rule by using the suggested algorithm.Finally，renal insufficiency diagnosis rules are mined.Feasibility of the method is demonstrated by a simple renal insufficiency diagnosis example.

Key words: dominance relation rough set, Variable Precision Rough Set（VPRS）, confidence, support number, renal insufficiency