南京市35家实验室糖化血红蛋白A1c检测结果的初步调查

目的了解南京市各医疗机构糖化血红蛋白A1c(HbA1c)检测方法及结果的可比性,分析室间变异和测定偏差,初步探讨误差原因和改进措施,为做好实验室结果互认工作提供依据。方法制备新鲜混合全血样本,确立靶值,并分发至南京市35家实验室,24 h内完成检测;按方法学分组统计分析各实验室结果;分别按美国病理学家协会(College of American Patholo-gists,CAP)的推荐标准(靶值±8%偏差)和"可接受总误差"标准(靶值±3.9%偏差)来判断结果是否可接受;以水平2样本HbA1c靶值6.5%为例观察结果的分布。结果高效液相色谱(HPLC)组CV为2.91%～4.48%,免疫比浊组为9.66%～11.10%,低压液相色谱(LPLC)组为11.6%～16.1%,微粒色谱组为10.4%～20.3%;按CAP标准以靶值±8%偏差来判断,三级医疗机构实验室合格率为78.6%,二级医疗机构实验室为31.5%;以靶值±3.9%偏差来判断时,三级医疗机构实验室合格率为42.8%,二级医疗机构实验室为10.5%;水平2样本在±8%偏差之内的有25家,占71.4%(25/35);在±3.9%偏差内的有15家,占42.9%(15/35)。结论南京市三级以上医疗机构HbA1c检测结果较一致,二级医疗机构检测结果差异较大;方法学差异在HbA1c检测中的确存在,但严格的室内质控和实验室间比对才是保证结果准确一致最重要的因素;各实验室特别是二级以下医疗机构实验室的质控意识仍有待加强,实验室间比对工作也有待进一步向基层医疗机构推广。

Preliminary investigation on the test results of glycosylated hemoglobin A1c from 35 laboratories in Nanjing

Objective To investigate the test methods and the comparability of the results of glycosylated hemoglobin A1c(HbA1c) from the clinical laboratories in Nanjing,analyze the inter-laboratory variation and the determination deviation,and explore the possible sources of error and improvement measures in order to provide the evidence for the mutual accredit of results from different laboratories.Methods Fresh whole blood samples were mixed and target value was established.The prepared blood samples were distributed to 35 laboratories in Nanjing,and the determinations for HbA1c were completed within 24 hours.The samples were divided into different groups according to methodology,and statistical analysis for the results was performed.The acceptability of the results was decided according to the criteria recommended by the College of American Pathologists(CAP),i.e.,the deviation within the range of 8% of target value and the "acceptable total error" within the range of 3.9% of target value.As the example,6.5% of target value was designated as "level 2" to observe the distribution of the test results.Results The coefficient of variation(CV) in the group of high performance liquid chromatography(HPLC),immunoturbidimetry,low pressure liquid chromatography(LPLC) and the microparticle color spectrum were 2.91% to 4.48%,9.66% to 11.10%,11.6% to 16.1% and 10.4% to 20.3%,respectively.The qualified rate of the test results from the laboratories of the top-grade hospitals and the secondary hospitals were 78.6% and 31.5%,respectively,judged by the criteria recommended by CAP,i.e.,deviation within the range of 8% of target value.However,the qualified rates were 42.8% and 10.5% respectively judged by the "acceptable total error" standard(the range of 3.9% of target value).For the values of "level 2",the qualified rates were 71.4%(25/35) and 42.9%(15/35) respectively.Conclusion The HbA1c results from the laboratories of the top-grade hospitals were more of a consensus,but there was large difference in the secondary hospitals.The disparity of methodology for determining the HbA1c level was really in presence,but the strict quality control for intra-laboratory and keeping the external quality assessment of the test results were still the most important for maintaining the accuracy and conformity.The consciousness of quality control should be strengthened in all the laboratories,especially for the laboratories of the secondary or primary hospitals,and the contrast between laboratories should be extended to primary medical institutions.