National Health Laboratory Service (NHLS), Department of Molecular Medicine and Haematology, University of the Witwatersrand (WITS), Johannesburg, South Africa.
Int J Lab Hematol. 2019 Apr;41(2):298-303. doi: 10.1111/ijlh.12973. Epub 2019 Jan 28.
Laboratory quality assurance (QA) includes internal quality control (IQC), external quality assurance (EQA) and quality improvement (QI). EQA identifies quality deviations and training needs. D-dimers are breakdown products of thrombus and results guide various clinical decisions.
The National Health Laboratory Service (NHLS) in South Africa performs the pathology tests for more than 80% of the population. The NHLS Quality Assurance Department distributed 301 questionnaires to laboratories enquiring about D-dimer testing. Two levels of STAGO and Siemens commercial D-dimer assay control material were distributed for analysis and returned results analysed.
A total of 64 (21.2%) completed questionnaires were returned and 26 (40.6%) laboratories were performing D-dimers with 25 (97%) subscribing to an EQA scheme. All laboratories reported results in D-dimer units with a negative result cut-off of ≤0.25 mg/L but various testing platforms were in use. All returned interpretations of analyses on the blinded control material were correct. The results were also within the respective reference ranges of the controls apart from three outliers. One laboratory obtained a result on STAGO pathological control that was above the cut-off of the control reference range but the reason for this error could not be identified. Another obtained results on the STAGO and on the Siemens normal controls that were both below the cut-off of the control reference range due to transcription errors.
The study demonstrated the feasibility of a local EQA scheme for D-dimers based on commercial control material that could mitigate against the cost of international EQA scheme participation.
实验室质量保证（QA）包括内部质量控制（IQC）、外部质量保证（EQA）和质量改进（QI）。EQA 可识别质量偏差和培训需求。D-二聚体是血栓的降解产物，检测结果可指导各种临床决策。
南非国家卫生实验室服务（NHLS）为超过 80%的人口提供病理检测服务。NHLS 质量保证部门向实验室分发了 301 份调查问卷，询问 D-二聚体检测情况。分发给实验室分析的是两种 STAGO 和西门子商业 D-二聚体检测试剂盒的控制材料，并对返回的结果进行了分析。
共收到 64 份（21.2%）完整的调查问卷，有 26 家（40.6%）实验室开展了 D-二聚体检测，其中 25 家（97%）实验室参加了 EQAS 计划。所有实验室都以 D-二聚体单位报告结果，阴性结果截断值为≤0.25mg/L，但使用的检测平台各不相同。所有实验室对盲法质控材料的分析结果解释均正确。除了三个离群值外，结果也都在各自控制参考范围内。一个实验室在 STAGO 病理质控品上的检测结果超过了控制参考范围的截止值，但无法确定该错误的原因。另一个实验室在 STAGO 和西门子正常控制品上的检测结果均低于控制参考范围的截止值，这是由于转录错误所致。
该研究表明，基于商业控制材料的本地 D-二聚体 EQAS 计划具有可行性，可降低参与国际 EQAS 计划的成本。
