摘要
目的 评价临床检验分析方法不精密度的要求。方法 利用临床检验质量控制预测模型 ,常用质量控制方法的功效函数图和工业过程能力指数的概念 ,确定了医学上重要的系统误差与过程能力指数之间的关系。结果 当临床检验对分析方法不精密度的要求为方法两倍的标准差 (s)小于允许总误差 (TEa) (即是 :2s<TEa)时 ,常用的质控方法对医学上重要的误差难以检出。统计质控方法功效函数的研究表明医学上重要误差大小必须至少是 3s时 ,才能落在功效曲线的平台附近 ,常用质控方法将易于检出。对于方法刚好满足 2s<TEa精密度标准 ,医学上重要误差将落在功效函数曲线的上升部位 ,且只有半数以下的机会检出它们。从“逆向工程”观点出发 ,2s<TEa标准是不恰当的 ,因为它没有考虑到常用质控方法性能的局限性。结论 分析方法的不精密度标准应是 4s<TEa,即要求精密度上提高至少两倍 。
Objective To assess imprecision requirements for analytical process in clinical laboratories. Methods The establishment of control procedures in detection of medically important systematic errors in relation to various values for the process capability index, by use of the quality control predictive value mode, the power function graph of commonly used control procedures and the industrial concept of process capability index.Results Current performance criteria for analytical methods are often based on two times the standard deviation (s) of the method be less than the allowable total error (TEa). When this criterion is minimally satisfied, commonly used control procedures cannot achieve reliable detection of medically important errors. Studies of the power functions for statistical quality-control (QC) procedures show that the magnitude of medically important errors must be at least 3s to fall near the plateau of the power curves and be readily detected by current QC procedures. For methods that just meet the precision criterion 2s less than TEa, however, medically important errors will fall on the rising portion of the power curves and typically be detected less than half of the time. From a “reverse engineering” perspective, the 2s less than TEa criterion is inadequate because it does not allow for the known performance limitations (lack of sensitivity) of commonly used control procedures..Conclusion A strong case can be made for using a criterion of at least 4s less than TEa, which calls for a twofold improvement in imprecision over, the current minimum requirements. This recommendation is consistent with current industrial guidelines for process capability and would lead to more reliable detection of medically important errors.
出处
《中国卫生统计》
CSCD
北大核心
2002年第6期328-331,共4页
Chinese Journal of Health Statistics
