The reliability of manufacturer-determined, instrument-specific international sensitivity index values for calculating the international normalized ratio.
The reliability of manufacturer-determined, instrument-specific international sensitivity index values for calculating the international normalized ratio.
复制标题
制造商确定的、仪器特定的用于计算国际标准化比率的国际灵敏度指数值的可靠性。
DOI：
10.1093/ajcp/102.1.128
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发表时间：
1994
影响因子：
3.5
通讯作者：
Olson,JD
中科院分区：
文献类型：
--
作者：
Cunningham,MT;Johnson,GF;Pennell,BJ;Olson,JD
一些凝血活酶制造商目前提供其试剂的仪器特定国际敏感性指数 (ISI) 值，允许临床实验室计算接受香豆素治疗的患者血浆样本的仪器特定国际标准化比值 (INR) 值。然而，如果使用制造商确定的 ISI 值，INR 的系统仪器间变异性将被消除的假设仍然没有得到证实。通过比较测量机械终点的仪器（纤维计）和测量光光学终点的仪器（MLA-700）获得的 INR 值来评估这一假设。使用制造商提供的三种具有仪器特定 ISI 值的凝血活酶试剂（ISI 范围，1.23–2.79）。对于三种试剂中的两种，纤维计 INR 值显着高于 MLA-700 INR 值 (P< .01)。对数凝血酶原时间比率图的分析表明，这种系统变异性是由不准确的制造商 ISI 值引起的。具有临床意义的是，不准确的 ISI 值在这两台仪器之间产生了大量不一致的 INR 值（> 47% 的血浆样本有一个 INR 值在推荐的治疗范围内，一个在推荐的治疗范围之外）。讨论了这些发现对口服抗凝药物实验室监测的意义。
Some thromboplastin manufacturers are currently supplying the instrument-specific international sensitivity index (ISI) values of their reagents, allowing clinical laboratories to calculate instrument-specific international normalized ratio (INR) values on plasma samples from patients receiving coumarin therapy. However, the assumption that systematic interinstrument variability in the INR would be eliminated if manufacturer-determined ISI values were used remains unsubstantiated. This assumption was evaluated by comparing INR values obtained on one instrument that measures a mechanical endpoint (fibrometer) with one that measures a photo-optical endpoint (MLA-700). Three thromboplastin reagents with instrument-specific ISI values supplied by the manufacturer (ISI range, 1.23–2.79) were used. For two of three reagents, the fibrometer INR values were significantly higher than the MLA-700 INR values (P< .01). Analysis of log prothrombin time ratio plots showed that this systematic variability was caused by inaccurate manufacturer ISI values. Of clinical significance is that the inaccurate ISI values produced a high number of discordant INR values between these two instruments (> 47% of plasma samples had one INR value within and one out of the recommended therapeutic range). The implication of these findings for laboratory monitoring of oral anticoagulation is discussed.