The method of National Committee for Clinical Laboratory Standards(NCCLS) is widely used for the daily quality control of the antimicrobial susceptibility test. This method, however, cannot detect the accidental error, although it is useful to detect the systematic error in the examination. We developed a computer program using the correlation between the various antimicrobial susceptibility test results to detect an accidental error. The combinations of the MIC results determined for two antimicrobial agents which showed a high correlation coefficient(≧0.7), were selected from 98 bacterial species(2122 strains) isolated from January 2000 to December 2000 at Oita Medical University Hospital. Subsequently, a total of 127 combinations of antimicrobial agents for 13 species were selected on the basis of acceptable correlation ranges. Then, the method were verified with 666 strains(5753 combinations) isolated during the period of January to June, 2001. Twenty-six strains(47 combinations) were identified as an unexpected result, and the occurrence of error were confirmed in 3 strains(12 combinations). These results suggest that this method which evaluated the correlation between MICs against different antimicrobial agents is applicable for the quality control of antimicrobial susceptibility testings.
[Rinsho Byori 50 : 706～711, 2002]
*1Department of Laboratory Medicine, Oita Medical University Hospital, Hasama, Oita. 879-5593
【Key Words】quality control(精度管理)，laboratory error(検査過誤)，correlation between antimicrobial susceptibilities(薬剤間相関)，principal component analysis(主成分分析)
受付2002年3月22日・受理2002年6月10日
*1～6大分医科大学医学部附属病院検査部，*7同 第二内科(〒879-5593 大分県大分郡挾間町医大が丘1-1)
E-mail :tueno@oita-med.ac.jp