Background

To mitigate the COVID-19 pandemic, countries worldwide have enacted unprecedented movement restrictions, physical distancing measures, and face mask requirements. Until safe and efficacious vaccines or antiviral drugs become widely available, viral testing remains the primary mitigation measure for rapid identification and isolation of infected individuals. We aimed to assess the economic trade-offs of expanding and accelerating testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) across the USA in different transmission scenarios.

Methods

We used a multiscale model that incorporates SARS-CoV-2 transmission at the population level and daily viral load dynamics at the individual level to assess eight surveillance testing strategies that varied by testing frequency (from daily to monthly testing) and isolation period (1 or 2 weeks), compared with the status-quo strategy of symptom-based testing and isolation. For each testing strategy, we first estimated the costs (incorporating costs of diagnostic testing and admissions to hospital, and salary lost while in isolation) and years of life lost (YLLs) prevented under rapid and low transmission scenarios. We then assessed the testing strategies across a range of scenarios, each defined by effective reproduction number (R_e), willingness to pay per YLL averted, and cost of a test, to estimate the probability that a particular strategy had the greatest net benefit. Additionally, for a range of transmission scenarios (R_e from 1·1 to 3), we estimated a threshold test price at which the status-quo strategy outperforms all testing strategies considered.

Findings

Our modelling showed that daily testing combined with a 2-week isolation period was the most costly strategy considered, reflecting increased costs with greater test frequency and length of isolation period. Assuming a societal willingness to pay of US$100 000 per YLL averted and a price of $5 per test, the strategy most likely to be cost-effective under a rapid transmission scenario (R_e of 2·2) is weekly testing followed by a 2-week isolation period subsequent to a positive test result. Under low transmission scenarios (R_e of 1·2), monthly testing of the population followed by 1-week isolation rather than 2-week isolation is likely to be most cost-effective. Expanded surveillance testing is more likely to be cost-effective than the status-quo testing strategy if the price per test is less than $75 across all transmission rates considered.

Interpretation

Extensive expansion of SARS-CoV-2 testing programmes with more frequent and rapid tests across communities coupled with isolation of individuals with confirmed infection is essential for mitigating the COVID-19 pandemic. Furthermore, resources recouped from shortened isolation duration could be cost-effectively allocated to more frequent testing.

Funding

US National Institutes of Health, US Centers for Disease Control and Prevention, and Love, Tito's.

中文翻译：

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美国 SARS-CoV-2 检测策略的成本效益比较：模型研究

 背景

为了缓解 COVID-19 大流行，世界各国颁布了前所未有的行动限制、保持身体距离的措施和佩戴口罩的要求。在安全有效的疫苗或抗病毒药物广泛普及之前，病毒检测仍然是快速识别和隔离感染者的主要缓解措施。我们的目的是评估在不同传播情况下在美国范围内扩大和加速严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 检测的经济权衡。

 方法

我们使用了一个多尺度模型，该模型结合了人群水平上的 SARS-CoV-2 传播和个体水平上的每日病毒载量动态，来评估八种监测检测策略，这些策略因检测频率（从每日检测到每月检测）和隔离期（1 或 1 个月）而异。 2 周），与基于症状的检测和隔离的现状策略进行比较。对于每种检测策略，我们首先估算了在快速和低传播情况下避免的成本（包括诊断检测和入院费用以及隔离期间的工资损失）和生命损失年数（YLL）。然后，我们评估了一系列场景中的测试策略，每个场景都由有效繁殖数 (R _e )、每个避免的 YLL 的支付意愿和测试成本来定义，以估计特定策略具有最大净收益的概率。此外，对于一系列传输场景（R _e从 1·1 到 3），我们估计了一个阈值测试价格，在该阈值测试价格下，现状策略优于所有考虑的测试策略。

 发现

我们的模型显示，每日测试与两周隔离期相结合是成本最高的策略，反映出随着测试频率和隔离期长度的增加，成本也会增加。假设社会愿意为每个避免的 YLL 支付 10 万美元，每次检测的价格为 5 美元，那么在快速传播情况下最有可能具有成本效益的策略（R _e为 2·2）是每周进行一次检测，然后进行 2 次检测。检测结果呈阳性后一周的隔离期。在低传播情况下（R _e为 1·2），每月对人群进行检测，然后进行 1 周隔离而不是 2 周隔离可能是最具成本效益的。如果在考虑的所有传输速率下每次测试的价格低于 75 美元，那么扩大的监视测试可能比现状测试策略更具成本效益。

 解释

广泛扩大 SARS-CoV-2 检测计划，在社区进行更频繁、更快速的检测，并隔离确诊感染者，对于缓解 COVID-19 大流行至关重要。此外，从缩短的隔离时间中收回的资源可以经济有效地分配给更频繁的测试。

 资金

美国国立卫生研究院、美国疾病控制和预防中心以及 Love, Tito's。