稳健统计方法及t检验法在活菌计数能力比对中的应用

为比较检验员活菌计数能力及常量法和微量法在活菌计数应用中是否存在差异，8名检验员于同时、同环境中对同一细菌培养物采用常量法和微量法进行活菌计数，采用稳健统计方法对不同人员相同方法的计数结果进行统计，将检验结果分为“满意”、“可疑”和“不满意”；采用t检验法对使用不同方法对同一样品的计数结果进行统计，将结果分为“差异显著”和“差异不显著”。稳健统计方法表明，用常量法进行检测，有6名检验员的检验结果全部满意，而微量法的结果中只有2名检验员获得了全部满意的结果；t检验法表明常量法和微量法之间存在显著差异。稳健统计方法及t检验法统计结果显示，不能用微量法代替常量法进行检验，个别检验员的活菌计数能力有待进一步提高。

Application of Robust Statistic Method and T Test of Proficiency Testing for Live Bacteria Counting

The test was aim to comprehensively grasp inspectors＇ ability of live bacteria counting and the differences among constant method and trace method in live bacteria. Each inspector counted bacteria in the same culture using two methods of constant and micro methods in the same environment at the same time. Then robust statistical analysis techniques of Z score values were used to statistically analyse live bacteria counting results of different inspectors using same method. Different inspectors＇test results were evaluated as ＂satisfactory＂, ＂suspicious＂ or ＂unsatisfactory＂. t test was used to statistically analyse live bacteria counting results of different methods but the same sample. Test results using different methods were evaluated as ＂significant difference＂ and ＂no significant difference＂. Three kinds of bacteria were detected by constant method, six inspectors＇ test results were all satisfactory. But, only two inspectors＇ test results were all satisfactory using micro method. Besides, results of t test showing differences among inspectors using micro method were more significant than that using constant method. The results of Z score and t test showed that it was no suitable to use micro method instead of constant method for test, and there were needs to be further improved for individual inspectors on ability of live bacteria counting.