METHODS: We used at total of 262 serum samples (197 pre-pandemic and 65 convalescent COVID-19), and three criteria to evaluate the rapid tests under standardized and optimal conditions: (i) Immunoglobulin G (IgG) specificity \"good\" if lower limit of the 95% confidence interval was ≥ 97.0%, \"acceptable\" if point estimate was ≥ 97.0%, otherwise \"not acceptable\". (ii) IgG sensitivity \"good\" if point estimate was ≥ 90.0%, \"acceptable\" if ≥ 85.0%, otherwise \"not acceptable\". (iii) User-friendliness \"not acceptable\" if complicated to perform or difficult to read result, otherwise \"good\". We also included partial evaluations of three automated immunoassay systems.
RESULTS: Sensitivity and specificity varied considerably; IgG specificity between 90.9% (85.9-94.2) and 100% (97.7-100.0), and IgG sensitivity between 53.8% (41.9-65.4) and 98.5% (91.0-100.0). Combining our evaluation criteria, none of the 28 rapid tests that detected IgG had an overall performance considered \"good\", seven tests were considered \"acceptable\", while 21 tests were considered \"not acceptable\". Four tests detected only total antibodies and were not given an overall evaluation. IgG sensitivity and/or specificity of the automated immunoassays did not exceed that of many rapid tests.
CONCLUSIONS: When prevalence is low, the most important analytical property is a test\'s IgG specificity, which must be high to minimize false positive results. Out of 32 rapid tests, none had a performance classified as \"good\", but seven were classified as \"acceptable\".
方法:我们总共使用了262份血清样本(197份大流行前和65份恢复期COVID-19),以及在标准化和最佳条件下评估快速测试的三个标准:(i)如果95%置信区间的下限≥97.0%,则免疫球蛋白G(IgG)特异性“良好”,如果点估计≥97.0%,则“可接受”,否则\"不可接受\"。(ii)如果点估计值≥90.0%,IgG敏感性“良好”,“可接受”如果≥85.0%,否则\"不可接受\"。(iii)如果执行复杂或难以阅读结果,则用户友好性“不可接受”,否则\“好\”。我们还包括三个自动免疫测定系统的部分评估。
结果:敏感性和特异性差异很大;IgG特异性在90.9%(85.9-94.2)和100%(97.7-100.0)之间,IgG敏感性在53.8%(41.9-65.4)和98.5%(91.0-100.0)之间。结合我们的评价标准,在检测到IgG的28项快速测试中,没有一项整体表现被认为是“良好”,七项测试被认为是“可接受的”,而21项测试被认为“不可接受”。四项测试仅检测到总抗体,未进行全面评估。自动化免疫测定的IgG灵敏度和/或特异性没有超过许多快速测试的灵敏度和/或特异性。
结论:当患病率较低时,最重要的分析特性是测试的IgG特异性,它必须很高,以尽量减少假阳性结果。在32次快速测试中,没有人的表现被归类为“好”,但有7人被归类为“可接受”。