贵阳市15套检测系统测定血清尿素氮的比对调查

Comparison of 15 Sets of Detection System for Determination of Serum Urea Nitrogen in Guiyang

目的：了解贵阳市部分医院临床实验室血清尿素氮检测的差异。方法：向贵阳市10家医院临床实验室15套检测系统发放添加不同浓度尿素氮标准物质的冰冻混合人血清样本5支，尿素氮定值为4.7、9.26、13.8、22.06和31.07 mmol/L，测定尿素氮水平，以水平2（含尿素氮标准物9.26 mmol/L）血清样本作为校准品，对15套检测系统进行校准后重新测量尿素氮水平，观察校准前后不同检测系统测定结果的变异（ CV）及测定结果与靶值的偏倚。结果：在统一校准前，实验室间各检测系统尿素氮测定结果的总CV为4.83%-6.8%，封闭检测系统测定结果的CV为3.95%-4.62%，非封闭检测系统测定结果的CV为5.23%-8.08%；统一校准后分别为3.18%-4.71%，1.96%-3.4%及3.59%-5.5%，校准前15套系统测定结果的总CV均高于校准后测定结果的总CV，无论是校准前还是校准后非封闭检测系统测定结果的CV均大于封闭检测系统；在统一校准前，各测定系统对4水平样本测定结果与靶值的相对偏倚分别为0.85%-27.23%、-3.55%-12.88、-3.5%-12.19%、-3.12%-11.04%；统一校准后分别为-1.7%-19.36%、-2.75%-10.06%、-3.26%-5.17、-3.54%-8.56%，比校准前减小。结论：各医院检验科各检测系统血清尿素氮测定结果的变异较大，校准后变异明显下降；封闭检测系统测定结果的可比性好，开放检测系统测定结果可比性较差。

Objective：To understand the difference of serum urea nitrogen detection in different labo-ratories in some hospitals in Guiyang. Methods：Five frozen human serum standard material with urea nitrogen fixed value being 4.7 ,9.26 ,13.8 ,22.06 and 31.07 mol/L were distributed to 15 sets of detection system of ten clinical laboratories in Guiyang. Urea nitrogen level was determined. With level 2 serum samples（containing urea nitrogen standard 9. 26 mmol/L）being calibrator,15 sets of detec-tion system was calibrated,after which the level of urea nitrogen was re-detected,and the results of variation（ CV）and the target value of bias before and after calibration were observed. Result：Before uniform calibration,the total CV was 4. 83% -6. 8%,the CV of closed detection systems results was 3 . 95% -4 . 62% and the CV of unclosed measurement systems results was 5 . 23% -8 . 08%. After u-niform calibration,the total CV was 3. 18% -4. 71%,the CV of closed detection systems results was 1 . 96% -3 . 4% and the CV of unclosed measurement systems results was 3 . 59% -5 . 5%. The total CV of the calibration results of the 15 sets of system before uniform calibration was higher than the total CV after the calibration. The results of CV were larger than those of the closed test system before and after calibration. Before uniform calibration,the relative bias of different measurement systems results were as follows：0 . 85% -27 . 23%,-3 . 55% -12 . 88 ,-3 . 5% -12 . 19% and -3 . 12% -11. 04%. After calibration,the relative bias of different measurement systems results were as follows：-1 . 7% -19 . 36%,-2 . 75% -10 . 06%,-3 . 26% -5 . 17 and -3 . 54% -8 . 56%. Conclu-sions：The test results of urea nitrogen from different laboratories vary significantly,especially for the results of unclosed measurement systems. The CV of each measurement system results decreased signif-icantly when the measurement systems were calibrated. The results of the closed detection system were better than that of the open system.