Poller Leon, Keown Michelle, Chauhan Nikhil, van den Besselaar Anton M H P, Tripodi Armando, Shiach Caroline, Jespersen Jorgen
European Concerted Action on Anticoagulation Central Facility, School of Biological Sciences, The University of Manchester, Manchester, United Kingdom.
Clin Chem. 2004 Mar;50(3):537-44. doi: 10.1373/clinchem.2003.019653. Epub 2004 Jan 6.
International Normalized Ratios (INRs) for prothrombin time obtained with the CoaguChek Mini and TAS (RapidPointCoag) PT-NC systems are markedly different and also differ from the "true" INR. There is therefore a need for local quality assessment (QA) of the two systems.
A set of 60 lyophilized artificially depleted and 60 lyophilized coumarin plasmas were tested at 10 centers on both point-of-care testing monitors. Subsets of three and five plasmas were selected as QA plasmas and compared with the remaining 55 to assess the relative ability of the systems to characterize performance at the individual centers. The incidence of aberrant results (outliers; >15% deviation from the true INR) was also recorded. The expected incidence with the QA plasmas was calculated and compared.
On both systems, INR with the common sets of 55 lyophilized plasmas varied considerably between centers. With the TAS PT-NC, subsets of five and three European Concerted Action on Anticoagulation (ECAA) artificially depleted plasmas gave good correlation with the 55 plasmas, but the coumarin plasmas performed less well. With the CoaguChek Mini, correlation was good with sets of five artificially depleted QA plasmas and reasonable with three but was less satisfactory with the coumarin plasmas. Outliers were detected with both types of plasmas on both test systems but with variable success.
With the TAS PT-NC, three ECAA artificially depleted lyophilized plasmas provided reliable QA, but five lyophilized coumarin plasmas were required. With the CoaguChek Mini, five artificially depleted plasmas gave reliable QA but coumarin plasmas gave poorer results. ECAA QA plasmas provide a local system for checking INRs obtained with monitors of both types.
使用CoaguChek Mini和TAS（RapidPointCoag）凝血酶原时间-国际标准化比值（PT-NC）系统获得的凝血酶原时间国际标准化比值（INR）明显不同，且与“真实”INR也存在差异。因此，需要对这两种系统进行本地质量评估（QA）。
在10个中心使用两种即时检测监测仪对一组60份冻干人工稀释血浆和60份冻干香豆素血浆进行检测。选择3份和5份血浆的子集作为QA血浆，并与其余55份血浆进行比较，以评估系统在各个中心表征性能的相对能力。还记录了异常结果（离群值；与真实INR偏差>15%）的发生率。计算并比较了QA血浆的预期发生率。
在这两种系统上，55份冻干血浆的常见组的INR在各中心之间差异很大。对于TAS PT-NC，5份和3份欧洲抗凝协作行动（ECAA）人工稀释血浆的子集与55份血浆具有良好的相关性，但香豆素血浆的表现较差。对于CoaguChek Mini，5份人工稀释QA血浆组的相关性良好，3份血浆组的相关性合理，但香豆素血浆组的相关性不太令人满意。在两种检测系统上，两种类型的血浆均检测到离群值，但成功率各不相同。
对于TAS PT-NC，3份ECAA人工稀释冻干血浆可提供可靠的QA，但需要5份冻干香豆素血浆。对于CoaguChek Mini，5份人工稀释血浆可提供可靠的QA，但香豆素血浆的结果较差。ECAA QA血浆提供了一个本地系统，用于检查使用这两种监测仪获得的INR。
