Koch D D, Oryall J J, Quam E F, Feldbruegge D H, Dowd D E, Barry P L, Westgard J O
Department of Pathology and Laboratory Medicine, Medical School, University of Wisconsin, Madison 53792.
Clin Chem. 1990 Feb;36(2):230-3.
Quality-control (QC) procedures (i.e., decision rules used, numbers of control measurements collected per run) have been selected for individual tests of a multitest analyzer, to see that clinical or "medical usefulness" requirements for quality are met. The approach for designing appropriate QC procedures includes the following steps: (a) defining requirements for quality in the form of the "total allowable analytical error" for each test, (b) determining the imprecision of each measurement procedure, (c) calculating the medically important systematic and random errors for each test, and (d) assessing the probabilities for error detection and false rejection for candidate control procedures. In applying this approach to the Hitachi 737 analyzer, a design objective of 90% (or greater) detection of systematic errors was met for most tests (sodium, potassium, glucose, urea nitrogen, creatinine, phosphorus, uric acid, cholesterol, total protein, total bilirubin, gamma-glutamyltransferase, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase) by use of 3.5s control limits with two control measurements per run (N). For the remaining tests (albumin, chloride, total CO2, calcium), requirements for QC procedures were more stringent, and 2.5s limits (with N = 2) were selected.
已为多测试分析仪的各项测试选择了质量控制（QC）程序（即所使用的决策规则、每次运行收集的控制测量次数），以确保满足临床或“医学实用性”的质量要求。设计适当QC程序的方法包括以下步骤：（a）以每项测试的“总允许分析误差”形式定义质量要求，（b）确定每个测量程序的不精密度，（c）计算每项测试的医学上重要的系统误差和随机误差，以及（d）评估候选控制程序的误差检测概率和错误拒绝概率。在将此方法应用于日立737分析仪时，对于大多数测试（钠、钾、葡萄糖、尿素氮、肌酐、磷、尿酸、胆固醇、总蛋白、总胆红素、γ-谷氨酰转移酶、碱性磷酸酶、天冬氨酸氨基转移酶、乳酸脱氢酶），通过使用3.5s控制限且每次运行进行两次控制测量（N），达到了90%（或更高）的系统误差检测设计目标。对于其余测试（白蛋白、氯、总二氧化碳、钙），QC程序的要求更为严格，因此选择了2.5s限值（N = 2）。
