Why Take a COVID-19 Test
With the constant threat of COVID-19 looming over everyone, many people are turning to home test kits to make sure they stay safe. But with the option of different types of COVID-19 tests, which is the most accurate, and which is the best one to use?
Currently there are two types of diagnostic COVID-19 tests used to diagnose if a patient has the virus, an antigen test and a PCR test. Both tests are conducted in a similar manner. (To find out more on the differences between the two tests, check out our “PCR vs Antigen Testing – What’s The Difference?” blog post). A test sample is taken from the upper respiratory tract and then is tested for different indicators of the COVID-19 virus.
Which COVID-19 Test Is The Most Accurate
Antigen tests are specifically used to test for viral antigens that indicate a viral infection. An antigen test can get results in about 15-30 minutes and it tests with 100% relative specificity and 91% relative sensitivity. With 100% specificity, this means that 100% of the time there is a negative test, it is a true negative and there is no chance of a false positive occurring. With a positive test, it is 91% accurate so 91% of the time a test is positive it will be correct, however there is a possibility of the test result showing positive when the patient actually does not have the virus, also known as a false negative. Antigen tests are best used for when there are no symptoms present but you have been in close contact with people who had the virus, and you are expecting your results to be negative.
PCR tests which stands for Polymerase Chain Reaction, test for genetic material of the virus. These tests can take anywhere from half an hour to a few days to get results depending on if a rapid PCR test is used or not. PCR tests can test samples with 98% specificity and 100% sensitivity. So 98% of the time there is a negative result, it is a true negative. Meaning there is a small chance the patient could actually be carrying the virus, otherwise known as a false positive. With 100% specificity, a test result that comes up positive will 100% of the time be a true positive with no chance of there being a false negative. PCR tests are typically used to diagnose if someone has the virus or to find out if someone recovering from the virus is still carrying it.
Out of the two, the most accurate tests are the PCR tests but they are usually more expensive and take slightly longer to get results. When deciding which test to use the user should also consider if they have symptoms and are looking for confirmation of the virus, or are simply getting tested for the absence of the virus. In the end, it is up to the user to choose the most convenient option. To get COVID-19 tested, look below to find a testing center near you. Or if you would like to get testing at home you can also find our Certified Teleservice for COVID-19 testing to be used with any EUA COVID-19 home test.