From the Harvard T.H. Chan School of Public Health, Emergency Preparedness Research Evaluation Program, Boston MA (RP-L); Georgetown University School of Medicine (KYJ); Georgetown University Medical Center, Department of Family Medicine (KWL); Georgetown University, Department of Health Systems Administration, Washington DC (JK, MAS).
J Am Board Fam Med. 2021 Feb;34(Suppl):S233-S243. doi: 10.3122/jabfm.2021.S1.200413.
Tests for Coronavirus disease 2019 (COVID-19) are intended for a disparate and shifting range of purposes: (1) diagnosing patients who present with symptoms to inform individual treatment decisions; (2) organizational uses such as "cohorting" potentially infected patients and staff to protect others; and (3) contact tracing, surveillance, and other public health purposes. Often lost when testing is encouraged is that testing does not by itself confer health benefits. Rather, testing is useful to the extent it forms a critical link to subsequent medical or public health interventions. Such interventions might be individual level, like better diagnosis, treatment, isolation, or quarantine of contacts. They might aid surveillance to understand levels and trends of disease within a defined population that enables informed decisions to implement or relax social distancing measures. In this article, we describe the range of available COVID-19 tests; their accuracy and timing considerations; and the specific clinical, organizational, and public health considerations that warrant different testing strategies. Three representative clinical scenarios illustrate the importance of appropriate test use and interpretation. The reason a patient seeks testing is often a strong indicator of the pretest probability of infection, and thus how to interpret test results. In addition, the level of population spread of the virus and the timing of testing play critical roles in the positive or negative predictive value of the test. We conclude with practical recommendations regarding the need for testing in various contexts, appropriate tests and testing methods, and the interpretation of test results.
新型冠状病毒疾病（COVID-19）检测的目的各不相同，且在不断变化：（1）诊断出现症状的患者，以告知个人治疗决策；（2）组织用途，如将可能感染的患者和员工“分组”以保护他人；（3）接触者追踪、监测和其他公共卫生目的。当鼓励进行检测时，往往会忽略检测本身并不能带来健康益处。相反，检测的有用程度取决于它是否形成后续医疗或公共卫生干预的关键环节。此类干预措施可能是个体层面的，例如更好地诊断、治疗、隔离或隔离接触者。它们可以帮助监测在特定人群中疾病的水平和趋势，从而能够做出实施或放宽社会距离措施的明智决策。在本文中，我们描述了一系列可用的 COVID-19 检测方法；它们的准确性和时间考虑因素；以及需要不同检测策略的具体临床、组织和公共卫生考虑因素。三个有代表性的临床场景说明了适当使用和解释测试的重要性。患者寻求检测的原因通常是感染前概率的强烈指标，因此如何解释检测结果。此外，病毒在人群中的传播程度和检测时间在检测的阳性或阴性预测值中起着关键作用。最后，我们根据在各种情况下进行检测的必要性、适当的测试和测试方法以及测试结果的解释提出了实用建议。
