62 people would test positive for COVID-19.Using summary results for people with no known exposure to COVID-19 in a bigger population of 10,000 people with no symptoms, where 50 (0.5%) of them really had COVID-19:

In people with no symptoms of COVID-19 the number of confirmed cases is expected to be much lower than in people with symptoms. Of these, 10 people (1.0%) would actually have COVID-19 (false negative result). 955 people would test negative for COVID-19.Of these, 5 people (11%) would not have COVID-19 (false positive result). 45 people would test positive for COVID-19.Using summary results for symptomatic people tested during the first week after symptoms began, if 1000 people with symptoms had the antigen test, and 50 (5%) of them really had COVID-19: No test met this standard when evaluated in people without symptoms. Two more tests met the WHO acceptable standard in one study each. Summary results (combined from more than one study per test brand) for seven tests met World Health Organization (WHO) standards as ‘acceptable’ for confirming and ruling out COVID-19 in people with signs and symptoms of COVID-19. In people who did not have COVID-19, antigen tests correctly ruled out infection in 99.6% of people with symptoms and 99.7% of people without symptoms.ĭifferent brands of tests varied in accuracy. For people with no symptoms, tests were most accurate in people likely to have been in contact with a case of COVID-19 infection (an average of 64% of confirmed cases had positive antigen tests). This is likely to be because people have the most virus in their system in the first days after they are infected. Tests were most accurate when used in the first week after symptoms began (an average of 82% of confirmed cases had positive antigen tests). In people with confirmed COVID-19, antigen tests correctly identified COVID-19 infection in an average of 73% of people with symptoms, compared to 55% of people without symptoms. Around 60% of studies took place in Europe. Studies investigated 49 different antigen tests.

The main results are based on 152 studies investigating a total of 100,462 nose or throat samples COVID-19 was confirmed in 16,822 of these samples. Studies could test people with or without symptoms.

People could be tested in hospital, in the community or in their own homes. We looked for studies that measured the accuracy of any commercially produced rapid antigen test in people who were also tested for COVID-19 using RT-PCR. We wanted to know whether commercially available, rapid point-of-care antigen tests are accurate enough to diagnose COVID-19 infection reliably, and to find out if accuracy differs in people with and without symptoms. Faster diagnosis of COVID-19 infection could allow people to take appropriate action more quickly, with the potential to reduce the spread of COVID-19, but it is important to understand how accurate they are and the best way to use them. In many places, rapid antigen tests have opened access to testing for many more people, with and without symptoms, and in locations other than healthcare settings. Currently, COVID-19 infection is confirmed by a laboratory test called RT-PCR, which uses specialist equipment and often takes at least 24 hours to produce a result. People with suspected COVID-19 need to know quickly whether they are infected, so that they can self-isolate, receive treatment, and inform close contacts. They come in disposable plastic cassettes, similar to over-the-counter pregnancy tests. These tests identify proteins on the virus in samples taken from the nose or throat.

do not require a specialist operator or setting andįor this review we were interested in rapid antigen tests, sometimes referred to as ‘lateral flow tests’.

are less expensive than standard laboratory tests.

are easy to perform, with a minimum amount of extra equipment or complicated preparation steps.

are portable, so they can be used wherever the patient is (at the point-of-care) or in non-healthcare settings such as in the home.

Rapid point-of-care tests aim to confirm or rule out COVID-19 infection in people with or without COVID-19 symptoms. What are rapid point-of-care antigen tests for COVID-19?

The accuracy of rapid antigen tests varies between tests that are produced by different manufacturers and there is a lack of evidence for many commercially available tests.

Rapid antigen tests are considerably less accurate when they are used in people with no signs or symptoms of infection, but do perform better in people who have been in contact with someone who has confirmed COVID-19.

People who test negative may still be infected.

Rapid antigen tests are most accurate when they are used in people who have signs or symptoms of COVID-19, especially during the first week of illness.

Covid rapid test false positive