Findings point to need for emphasis on other public health measures to prevent transmission
RESEARCH TRIANGLE PARK, N.C. — Researchers at RTI International, a nonprofit research institute, have released findings as part of a special collection of systematic and rapid reviews by Cochrane, a global network of researchers, evaluating the effectiveness and accuracy of screening programs for SARS‐CoV‐2 — the virus that causes COVID-19. The researchers evaluated over 20 studies on universal screening methods. Their findings show that screening could potentially miss a high proportion of infected individuals and could also increase the risk of identifying false positive cases, leading to unnecessary isolation.
“Our research shows that the likelihood of missing a person who may have COVID-19 through screening is extremely high,” said Meera Viswanathan, Ph.D., an expert in systemic review methodology at RTI and the lead author on the study. “Because screening is likely to miss many people who are infected, public health measures such as face coverings, physical distancing, and quarantine for those who have had contact with an infected person remain critical.”
The findings, released through part of a media briefing by Cochrane, found that one-time screening approaches could potentially miss anywhere from 20-100% of people infected with COVID-19. Throughout the pandemic, screening has been used in some clinics, workplaces, airports, or schools with the goal of reducing further transmission. Screening methods for COVID‐19 can include temperature checks, a brief travel history or exposure questionnaire, or in some cases a rapid laboratory test.
Viswanathan shared that for screening to be effective it needs to incorporate three key measures: screening methods that are more sensitive and accurate, a robust public health infrastructure with a testing plan put into place, and public buy in — she emphasized that testing will not succeed without public acceptance.
“Currently, when someone is screened negative, the assumption is that they do not have COVID-19. Because asymptomatic spread is so common, we cannot make that assumption,” said Viswanathan. “If more accurate screening methods are developed in the future, and they are going to be used as a tool to find COVID-19 cases, they should be followed up with measures like testing and isolation for positive cases and quarantine for those suspected to be infected.”
The researchers also concluded that further research is needed on more comprehensive symptom and risk assessments, rapid laboratory tests, and combinations of screening approaches.
Cochrane’s special collection includes three rapid reviews of the evidence on measures that aim to prevent and control the spread of COVID-19.
To read the rapid review, click here.
To watch a short video by Viswanathan explaining the review, click here.
About Cochrane
Cochrane is a global independent network of researchers, professionals, patients, carers and people interested in health. Cochrane produces reviews which study all of the best available evidence generated through research and make it easier to inform decisions about health. These are called systematic reviews. Cochrane is a not-for profit organization with collaborators from more than 130 countries working together to produce credible, accessible health information that is free from commercial sponsorship and other conflicts of interest. Our work is recognized as representing an international gold standard for high quality, trusted information.
About RTI International
RTI International is an independent, nonprofit research institute dedicated to improving the human condition. Clients rely on us to answer questions that demand an objective and multidisciplinary approach — one that integrates expertise across the social and laboratory sciences, engineering and international development. We believe in the promise of science, and we are inspired every day to deliver on that promise for the good of people, communities and businesses around the world. For more information, visit www.rti.org.
