Institute for Advanced Studies, Vienna, Austria.
London School of Economics and Political Science, London, UK.
BMC Public Health. 2023 Mar 16;23(1):506. doi: 10.1186/s12889-023-15364-w.
In October 2020, amidst the second COVID-19 epidemic wave and before the second-national lockdown, Austria introduced a policy of population-wide point-of-care lateral flow antigen testing (POC-LFT). This study explores the impact of this policy by quantifying the association between trends in POC-LFT-activity with trends in PCR-positivity (as a proxy for symptomatic infection), hospitalisations and deaths related to COVID-19 between October 22 and December 06, 2020.
We stratified 94 Austrian districts according to POC-LFT-activity (number of POC-LFTs performed per 100,000 inhabitants over the study period), into three population cohorts: (i) high(N = 24), (ii) medium(N = 45) and (iii) low(N = 25). Across the cohorts we a) compared trends in POC-LFT-activity with PCR-positivity, hospital admissions and deaths related to COVD-19; b) compared the epidemic growth rate before and after the epidemic peak; and c) calculated the Pearson correlation coefficients between PCR-positivity with COVID-19 hospitalisations and with COVID -19 related deaths.
The trend in POC-LFT activity was similar to PCR-positivity and hospitalisations trends across high, medium and low POC-LFT activity cohorts, with association with deaths only present in cohorts with high POC-LFT activity. Compared to the low POC-LFT-activity cohort, the high-activity cohort had steeper pre-peak daily increase in PCR-positivity (2.24 more cases per day, per district and per 100,000 inhabitants; 95% CI: 2.0-2.7; p < 0.001) and hospitalisations (0.10; 95% CI: 0.02, 0.18; p = 0.014), and 6 days earlier peak of PCR-positivity. The high-activity cohort also had steeper daily reduction in the post-peak trend in PCR-positivity (-3.6; 95% CI: -4.8, -2.3; p < 0.001) and hospitalisations (-0.2; 95% CI: -0.32, -0.08; p = 0.001). PCR-positivity was positively correlated to both hospitalisations and deaths, but with lags of 6 and 14 days respectively.
High POC-LFT-use was associated with increased and earlier case finding during the second Austrian COVID-19 epidemic wave, and early and significant reduction in cases and hospitalisations during the second national lockdown. A national policy promoting symptomatic POC-LFT in primary care, can capture trends in PCR-positivity and hospitalisations. Symptomatic POC-LFT delivered at scale and combined with immediate self-quarantining and contact tracing can thus be a proxy for epidemic status, and hence a useful tool that can replace large-scale PCR testing.
2020 年 10 月，正值第二波 COVID-19 疫情期间，在第二次全国封锁之前，奥地利推出了一项全民即时检测点侧向流动抗原检测（POC-LFT）政策。本研究通过量化 POC-LFT 活跃度与 PCR 阳性率（作为症状感染的替代指标）、住院和 COVID-19 相关死亡之间的趋势之间的关联，来探讨该政策的影响。
我们根据 POC-LFT 活跃度（研究期间每 10 万居民进行的 POC-LFT 次数）将 94 个奥地利区分为三个人群队列：（i）高（N=24），（ii）中（N=45）和（iii）低（N=25）。在各个队列中，我们 a）比较了 POC-LFT 活跃度与 PCR 阳性率、住院和 COVID-19 相关死亡之间的趋势；b）比较了疫情高峰前后的疫情增长率；c）计算了 PCR 阳性率与 COVID-19 住院和 COVID-19 相关死亡之间的 Pearson 相关系数。
POC-LFT 活性趋势与高、中、低 POC-LFT 活性队列中的 PCR 阳性率和住院率趋势相似，仅在 POC-LFT 活性高的队列中与死亡率相关。与低 POC-LFT 活性队列相比，高 POC-LFT 活性队列的 PCR 阳性率在疫情高峰前的每日增长更为陡峭（每个区每 10 万居民每天增加 2.24 例；95%CI：2.0-2.7；p<0.001）和住院率（0.10；95%CI：0.02，0.18；p=0.014），PCR 阳性率的高峰提前了 6 天。高 POC-LFT 活性队列在疫情高峰后的 PCR 阳性率和住院率下降趋势也更为陡峭（-3.6；95%CI：-4.8，-2.3；p<0.001）和住院率（-0.2；95%CI：-0.32，-0.08；p=0.001）。PCR 阳性率与住院和死亡均呈正相关，但存在 6 天和 14 天的滞后。
高 POC-LFT 使用与奥地利第二波 COVID-19 疫情期间的病例发现增加和提前有关，以及第二次全国封锁期间的病例和住院人数的早期和显著减少。在初级保健中推广有症状的 POC-LFT 的国家政策可以捕捉到 PCR 阳性率和住院率的趋势。大规模实施有症状的 POC-LFT，并结合立即自我隔离和接触者追踪，可以作为疫情状况的代表，因此是一种有用的工具，可以替代大规模的 PCR 检测。
