How Accurate Are Rapid COVID Tests?

Here in Australia, there are two tests that are commonly used to detect whether someone is carrying the COVID-19 virus. 

The first is the polymerase chain reaction (PCR) test that is considered the gold standard for accuracy by the Centers for Disease Control and Prevention (CDC) and is performed by a healthcare professional with results available after 24 hours. 

The other test became available to the public after November 1st and is known as a rapid covid test or a rapid antigen (RA) test. This test can be done by yourself at home, with results available between 20-30 minutes or 16 minutes with fast acting COVID-19 Rapid Test Kits

But do rapid covid tests have the PCR test accuracy? 

The answer is complicated as many factors affect the accuracy of a rapid COVID test, all of which are listed below:  

 

Chances of a rapid test giving a false negative 

The chances of a rapid COVID test giving a false negative (a negative COVID result when it is actually positive) depends on factors such as; the brand of test you use, how accurately you follow the instructions and whether or not you have any Symptoms of COVID-19. 

Always check the certificate of the test kit you use to make sure a valid medical body recognises it. All Medcart’s test kit abide by the Rapid Antigen Self-Testing guidelines set by the Australian Government Department of Health. 

Most false negatives are actually caused by people not following instructions carefully. Whether using a nasal or saliva swab, make sure to carefully follow the instructions provided every time.  

 

Accuracy for people with COVID-19 symptoms

According to a 2021 rapid antigen test case study, out of the people who were confirmed to have COVID-19, an average of 72% were accurately diagnosed using rapid antigen tests. 

However, this statistic increases the longer the person has had the virus, with one week being the most effective. The tests also increase in accuracy drastically when used repeatedly.

A recent American study tested college students and employees every three days and found that the rapid antigen tests successfully identified 98 per cent of COVID infections. This is on par with the accuracy of a PCR test. 

 

Accuracy for people without COVID-19 symptoms

For people without symptoms, the results of accuracy in case studies vary more widely than people with symptoms. 

Researchers found that the accuracy of those without COVID symptoms ranged from 40 to 74 per cent when using rapid covid tests. 

Just like those with symptoms, this accuracy can be increased with regular testing, following the instructions carefully and using validated brands of covid test kits. 

 

How accurate are other COVID-19 tests?

Different brands of rapid covid tests produce different results of accuracy, so it's important to choose a brand that works for your needs. 

Most brands that are validated (check the certificate) are met by standards prepared by the World Health Organization (WHO). 

Roche and Abbot are amongst the two brands from a Table of Brand Effectiveness 

 

PCR test

A PCR test features the highest standard of accuracy that is recognised by the Australian government in confirming that a person carries the COVID-19 virus. Many other international governments also require a PCR test be taken before entry into the country. 

Unfortunately, the administration of the PCR test has been privatised in Australia and is not paid for by the government. The average price for a PCR test is around $150 per person. 

Antibody tests

Antibody tests are performed by health professionals and involve taking a blood sample. The test determines whether your body carries specific antibodies that are only produced in response to the COVID-19 virus. 

This test can determine whether you have previously had covid at any point in your life, even if you did not feel any symptoms. 

 

Computed tomography (CT) scans

Health clinics perform this advanced scan as diagnosis used for lung disease treatment. Whilst it cannot specifically detect the COVID virus (results vary), it can detect any changes to the lungs. 

It is used primarily for pneumonia diagnosis, but some patients have reported changes in lung tissue due to COVID. 

 

Summary: 

 

Rapid covid tests are most effective when used regularly (at least once every three days). Whether or not you have symptoms, using the right brand and carefully following instructions will lead to accuracy on par with a PCR (around 98 per cent accuracy) See Our Range of Rapid at Home Covid Tests and keep safe.