The surge of the delta COVID-19 variant is driving sales of at-home COVID-19 test kits, which offer quick and fairly accurate results — if you use them correctly. Here, we answer some of the common questions about the quality of at-home tests, how to use them and what to do with the results.

Are at-home COVID test kits accurate? How do they compare to lab or doctor’s office tests?

Although there are many different COVID-19 tests available, they can generally be broken down into two types: molecular and antigen tests.

Molecular tests (nucleic acid amplification tests or NAAT) are usually processed in a laboratory and are generally more accurate than antigen tests, but results can take longer.

At-home rapid tests are antigen tests, which use a different mechanism to detect infection. These tests can be processed right in your home using a kit that appears similar to an at-home pregnancy test and gives results within 10-15 minutes.

Antigen tests are still fairly accurate, particularly when someone is experiencing symptoms and their viral load is very high. However, they can be less accurate in settings where someone has a lower viral load, such as in an asymptomatic individual, which could lead to false negative test results. You could have a false negative result if, for example, you test yourself too soon after you’ve been exposed to someone with COVID-19, or if you test when you have no symptoms.

Is one at-home COVID-19 test better than another?

Each test maker is required to submit some clinical data about the sensitivity (the ability of a test to detect a true positive) and the specificity (the ability of the test to detect a true negative) of the test. Because all the at-home COVID-19 tests are authorized under an Emergency Use Authorization, the performance of individual tests has not been as rigorously tested by the U.S. Food and Drug Administration — so it’s really difficult to say if one is “better” than another.

Are there any advantages to testing at home?

The major advantage is comfort and convenience — and the ability to get test results within 10-15 minutes.

Should you test at home for COVID-19 if you have no symptoms? If, for example, you had close contact or are looking to take a trip.

At-home testing can be useful in these circumstances, although it’s important to understand the limitations of the test — there’s a possibility for a false negative test, especially if you test too early after a possible exposure.

Serial testing — meaning repeating the test several days later — can help to improve accuracy.

What steps should you follow to ensure you’re doing an at-home COVID-19 test properly?

It’s very important to follow the instructions from the manufacturer carefully. Read through the instructions and be sure you understand prior to opening the test kit. Wash your hands and surfaces before starting the test.

If you don’t swab the nostrils properly, you may end up with a false negative test, so again, follow the instructions in the kit. You may feel uncomfortable swabbing this deep into your nose or the nose of a loved one, but swabbing is fairly quick, and doing it correctly will improve the likelihood of an accurate test.

What should you do if your at-home COVID-19 test is positive?

If your at-home test is positive, you should notify your health care provider and follow CDC guidelines for quarantine and isolation. It's also important to notify anyone you have been in close contact with so they can take the proper steps of testing and quarantine to help limit the spread of infection to others.

Does a negative home test mean you’re in the clear?

If you followed the instructions of the test carefully and you get a negative result, it’s unlikely that you have COVID-19 at that time. However, there are some circumstances where you may get a false negative result, particularly if you test too early in the course of the infection (when viral load is not as high). If you are concerned about this, you could repeat the test a few days later.

How much do at-home tests cost? What if you can’t afford the cost?

Roughly $20 to $40. If you can't afford the cost of an at-home test, free COVID-19 testing is available at multiple locations.