Abstract

To diagnose gestational diabetes mellitus (GDM), plasma glucose measurements during oral glucose tolerance test (OGTT) put high demands on the methods in terms of accuracy. The aim was to evaluate and compare diagnostic performance of a point-of-care test and a glucose hexokinase laboratory method. Using risk-based screening, 175 pregnant women were included. They underwent a 75 g OGTT in their 28th (median) week of gestation. Venous blood was collected in two different tubes. Plasma glucose was measured on Cobas c701 and in duplicates on AccuChek Inform II (both methods from Roche Diagnostics). Accuracy was assessed by participating in external control programs with reference method assigned values. The methods were compared for all samples (n = 512) by regression analysis; slope of 0.90 (95% CI: 0.89–0.92), intercept of 0.12 (95% CI: 0.011–0.22) and r_s of 0.968. The average bias between AccuChek Inform II and Cobas c701 was −8%. The proportion of women diagnosed with GDM was 25% based on AccuChek Inform II versus 55% for Cobas c701. Results from the external control program showed a bias of approximately 5% for Cobas c701 and no significant bias for AccuChek Inform II. Cobas c701 showed a large bias both towards Accu-Chek Inform II and the reference method used in the external control program, clearly exceeding the desirable bias of <2.6%. The lack of accuracy has great implications on either over- or under-diagnosis of GDM.

摘要

为了诊断妊娠糖尿病（GDM），口服葡萄糖耐量试验（OGTT）期间的血糖测量对方法的准确性提出了很高的要求。目的是评估和比较即时检验和葡萄糖己糖激酶实验室方法的诊断性能。使用基于风险的筛查，纳入了 175 名孕妇。他们在妊娠第 28 周（中位数）接受了 75 g OGTT。将静脉血收集在两个不同的试管中。在 Cobas c701 上测量血浆葡萄糖，并在 AccuChek Inform II 上重复测量（两种方法均来自 Roche Diagnostics）。通过参与具有参考方法指定值的外部控制计划来评估准确性。对所有样品的方法进行了比较（n = 512) 通过回归分析；斜率为 0.90（95% CI：0.89–0.92），截距为 0.12（95% CI：0.011–0.22），r _s为 0.968。AccuChek Inform II 和 Cobas c701 之间的平均偏差为 -8%。根据 AccuChek Inform II，诊断为 GDM 的女性比例为 25%，而 Cobas c701 为 55%。外部控制程序的结果显示，Cobas c701 的偏差约为 5%，而 AccuChek Inform II 没有显着偏差。Cobas c701 对 Accu-Chek Inform II 和外部控制程序中使用的参考方法都表现出很大的偏差，明显超过了小于 2.6% 的理想偏差。缺乏准确性对 GDM 的过度诊断或诊断不足都有很大影响。