Department of Family Medicine and Population Health (FAMPOP), Centre for General Practice, University of Antwerp, Antwerpen, Belgium
Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
BMJ Open. 2023 May 2;13(5):e069997. doi: 10.1136/bmjopen-2022-069997.
To validate a rapid serological test (RST) for SARS-CoV-2 antibodies used in seroprevalence studies in healthcare providers, including primary healthcare providers (PHCPs) in Belgium.
A phase III validation study of the RST (OrientGene) within a prospective cohort study.
Primary care in Belgium.
Any general practitioner (GP) working in primary care in Belgium and any other PHCP from the same GP practice who physically manages patients were eligible in the seroprevalence study. For the validation study, all participants who tested positive (376) on the RST at the first testing timepoint (T1) and a random sample of those who tested negative (790) and unclear (24) were included.
At T2, 4 weeks later, PHCPs performed the RST with fingerprick blood (index test) immediately after providing a serum sample to be analysed for the presence of SARS-CoV-2 immunoglobulin G antibodies using a two-out-of-three assay (reference test).
The RST accuracy was estimated using inverse probability weighting to correct for missing reference test data, and considering unclear RST results as negative for the sensitivity and positive for the specificity. Using these conservative estimates, the true seroprevalence was estimated both for T2 and RST-based prevalence values found in a cohort study with PHCPs in Belgium.
1073 paired tests (403 positive on the reference test) were included. A sensitivity of 73% (a specificity of 92%) was found considering unclear RST results as negative (positive). For an RST-based prevalence at T1 (13.9), T2 (24.9) and T7 (70.21), the true prevalence was estimated to be 9.1%, 25.9% and 95.7%, respectively.
The RST sensitivity (73%) and specificity (92%) make an RST-based seroprevalence below (above) 23% overestimate (underestimate) the true seroprevalence.
NCT04779424.
验证一种用于医疗保健提供者血清流行率研究（包括比利时基层医疗保健提供者（PHCP））的 SARS-CoV-2 抗体快速血清学检测（RST）。
前瞻性队列研究中的 RST（东方基因）的 III 期验证研究。
比利时基层医疗保健。
在比利时从事基层医疗保健的任何全科医生（GP）以及同一 GP 诊所中实际管理患者的任何其他 PHCP 都有资格参加血清流行率研究。对于验证研究，所有在第一次检测时间点（T1）上 RST 检测呈阳性（376 人）的参与者以及随机选择的 RST 检测呈阴性（790 人）和不确定（24 人）的参与者均被纳入。
4 周后，即 T2，PHCP 使用指尖采血（索引测试）进行 RST，之后立即提供血清样本，使用两管三检法（参考测试）分析 SARS-CoV-2 免疫球蛋白 G 抗体的存在。
使用逆概率加权来纠正缺失的参考测试数据，从而估计 RST 的准确性，并且对于 RST 不确定的结果，将其视为敏感性为阴性，特异性为阳性。使用这些保守的估计值，同时估计 T2 和基于 RST 的比利时 PHCP 队列研究中的流行率值的真实血清流行率。
共纳入 1073 对检测（参考测试阳性 403 对）。考虑到 RST 不确定的结果为阴性（阳性），发现 RST 的敏感性为 73%（特异性为 92%）。对于 T1（13.9%）、T2（24.9%）和 T7（70.21%）的基于 RST 的流行率，真实流行率估计分别为 9.1%、25.9%和 95.7%。
基于 RST 的血清流行率低于（高于）23%时，RST 的敏感性（73%）和特异性（92%）会导致对真实血清流行率的高估（低估）。
NCT04779424。
