血浆肌酐两种测定方法偏倚的比较

Comparison of two methods in detecting serum creatinine

目的:比较肌酐酶法和干化学法测定血浆肌酐结果的一致性,并对其进行偏倚评估。方法:依据美国临床实验室标准化委员会(NCCLS)EP9-A文件方案,每天选取临床样本8份,分别用两种方法测定样本肌酐含量,共测定6天,记录检验结果,以肌酐酶法为对比方法,对干化学法进行评估。去除离散值,计算线性方程和相关系数,进行配对t检验和偏倚评估。结果:肌酐酶法测定血浆肌酐明显高于干化学法(P<0.001),但两法具有正相关关系,其回归方程为∧Y=-3.449 4+0.929 6X,r2=0.993 2。肌酐浓度为100μmol/L、500μmol/L、900μmol/L时,干化学法的相对偏倚分别为10.5%、7.7%、7.4%。结论:两种方法测定血浆肌酐的结果差异有显著性,但具有良好的相关性,因此必须对肌酐测定的不同方法建立不同的参考值范围或进行方法间的校正。

Objective：To analyze the correlation between creatinine enzyme and dry chemistry method in detection of blood plasma creatinine and to estimate the bias between the two methods. Methods： According to the guideline approved by the National Committee for Clinical Laboratory Standards（NCCLS） ,48 patients＇ samples were analyzed in 6 operating days and each sample was analyzed in duplicate using both creatinine enzyme and dry chemistry methods. The dry chemistry method was evaluated with creatinine enzyme method acting as control. The duplicates were assessed with each method within the same run. The coefficient of correlation was calculsted as well as the pias. Results： There was a significant difference between the enzyme and dry chemical method in blood creafinine determination（ P 〈0.001 ） ,but they had a positive relativity; its linear equation was Y=-3. 449 4 ＋ 0. 929 6X and r^2 = 0.993 2. When the concentration of creatinine was 100μmol/L,500μmol/L and 900 μmol/L, the relative bias of dry chemistry method was 10.5% ,7.7% ,7.4%. Conclusions：The results were significantly different in detection of serum creatinine with the two different methods, but its correlation was good. The Laboratory must establish its own reference ranges for different methods or practice an emendation between the two methods.