Yang W, Hosgood G, Luobikis K, Paul A
The Animal Hospital Murdoch University, Murdoch Dr, Murdoch, Western Australia 6150, Australia.
Anderson Moores Veterinary Specialists Ltd, Winchester, UK.
Aust Vet J. 2018 Oct;96(10):379-384. doi: 10.1111/avj.12746.
To determine the agreement, sensitivity, specificity and accuracy of prothrombin (PT) and activated partial thromboplastin time (aPTT) using the point-of-care analyser SCA2000™ with IDEXX Coag Dx™ cartridges against a reference laboratory (STAGO Start 4®) in canine blood.
Citrated blood samples from 47 dogs were submitted for PT and aPTT measurements. The STAGO was taken as the gold standard and sensitivity, specificity and accuracy were calculated. Agreement between the IDEXX and STAGO test results was compared using Bland-Altman analysis and Passing-Bablok regression.
The IDEXX cartridges had a sensitivity of 92% (95% confidence interval (CI) 62-100%) and specificity of 98% (95% CI 87-100%; n = 54 samples). aPTT sensitivity was 100% (95% CI 63-100%) and specificity was 47% (95% CI 30-65%, n = 42 samples). The accuracy of IDEXX cartridges compared with the STAGO Start 4 was 96% (95% CI 91-100%) for PT and 57% (95% CI 42-72%) for aPTT. Agreement was moderate-good for PT measurements within the reference range (RR). Agreement was poor for PT measurements outside of the RR and for aPTT measurements within and outside the RR. The bias between measurements from the two machines was inconsistent.
PT results from the point-of-care IDEXX were generally reliable for diagnosing or excluding a coagulopathy. The aPTT IDEXX sensitivity was excellent but the specificity was poor. Bland-Altman analysis and Passing-Bablok regression indicated an inconsistent bias between the two measurements and one measurement cannot be reliably converted to the other.
使用配备IDEXX Coag Dx™检测卡的即时检测分析仪SCA2000™，针对犬类血液，以参考实验室（STAGO Start 4®）为对照，确定凝血酶原（PT）和活化部分凝血活酶时间（aPTT）的一致性、敏感性、特异性和准确性。
提交47只犬的枸橼酸盐抗凝血样本进行PT和aPTT检测。以STAGO检测结果作为金标准，并计算敏感性、特异性和准确性。使用Bland-Altman分析和Passing-Bablok回归比较IDEXX和STAGO检测结果之间的一致性。
IDEXX检测卡的敏感性为92%（95%置信区间（CI）62 - 100%），特异性为98%（95% CI 87 - 100%；n = 54份样本）。aPTT的敏感性为100%（95% CI 63 - 100%），特异性为47%（95% CI 30 - 65%，n = 42份样本）。与STAGO Start 4相比，IDEXX检测卡的PT准确性为96%（95% CI 91 - 100%），aPTT准确性为57%（95% CI 42 - 72%）。在参考范围内（RR），PT测量的一致性为中度良好。在RR之外的PT测量以及RR之内和之外的aPTT测量中，一致性较差。两台仪器测量结果之间的偏差不一致。
即时检测的IDEXX的PT结果在诊断或排除凝血病方面通常可靠。IDEXX的aPTT敏感性极佳，但特异性较差。Bland-Altman分析和Passing-Bablok回归表明两次测量之间存在不一致的偏差，且一次测量结果不能可靠地转换为另一次测量结果。
