How accurate are COVID-19 home test kits?

Author: Elsa Bosco  |  Last update: Saturday, November 20, 2021

COVID-19
Common question

How accurate are COVID-19 home test kits?

Some of the at-home antigen tests have an overall sensitivity of roughly 85 percent, which means that they are catching roughly 85 percent of people who are infected with the virus and missing 15 percent. In some studies, their real-world performance has been even lower.

Are saliva tests just as effective as nasal swabs to diagnose COVID-19?

Saliva testing for coronavirus disease 2019 (COVID-19) is as effective as the standard nasopharyngeal tests, according to a new study by investigators at McGill University.

Are there any at-home tests for COVID-19?

Yes. There are now COVID-19 tests available for purchase online or in a store that can be used completely at home. At-home tests allow you to collect your own sample and test it with a system that gives you results in minutes at home.

What are consequences of a false negative COVID-19 test?

Risks to a patient of a false negative test result include: delayed or lack of supportive treatment, lack of monitoring of infected individuals and their household or other close contacts for symptoms resulting in increased risk of spread of COVID-19 within the community, or other unintended adverse events.

How accurate is the At-home BinaxNOW COVID-19 test?

Accuracy: The BinaxNOW test correctly gave a positive result 84.6% of the time compared to PCR. In the same study, the test correctly gave a negative result 98.5% of the time. Availability: The BinaxNOW test costs $24 for two tests, which are meant to be used on the same person within three days (serial testing).

How Accurate Were These Home COVID-19 Test Kits?

How accurate is the BinaxNOW rapid test compared to PCR?

Accuracy: The BinaxNOW test correctly gave a positive result 84.6% of the time compared to PCR. In the same study, the test correctly gave a negative result 98.5% of the time.

Can At-home COVID-19 antigen tests give a false negative?

"Rapid antigen tests can easily miss asymptomatic infection. In fact, they're actually likely to be false negative in that time period and many are approved only for use in people with symptoms.

Does a negative result rule out the possibility of COVID-19?

A negative result does not rule out COVID-19 and should not be used as the sole basis for treatment or patient management decisions. A negative result does not exclude the possibility of COVID-19.

Can someone test negative and later test positive on a viral test for COVID-19?

Yes, it is possible. You may test negative if the sample was collected early in your infection and test positive later during this illness. You could also be exposed to COVID-19 after the test and get infected then. Even if you test negative, you still should take steps to protect yourself and others. See Testing for Current Infection for more information.

Can the COVID-19 molecular test give false negatives?

Molecular tests are typically highly sensitive for the detection of the SARS-CoV-2 virus. However, all diagnostic tests may be subject to false negative results, and the risk of false negative results may increase when testing patients with genetic variants of SARS-CoV-2.

Is at-home specimen collection or testing available for COVID-19?

Yes. At-home testing and collection allow you to collect a specimen at home and either send it to a testing facility or preform the test at home.

What are some of the common symptoms of the COVID-19 disease?

Symptoms may include: fever or chills; cough; shortness of breath; fatigue; muscle and body aches; headache; new loss of taste or smell; sore throat; congestion or runny nose; nausea or vomiting; diarrhea.

How long does it take to show symptoms after you have been exposed to COVID-19?

Symptoms may appear 2-14 days after exposure to the virus. If you have fever, cough, or other symptoms, you might have COVID-19.

Have saliva tests been approved by FDA as a sample for the coronavirus disease testing?

This is the fifth test that the FDA has authorized that uses saliva as a sample for testing. Testing saliva eliminates the need for nasopharyngeal swabs, which have also been prone to shortages, and alleviates the patient discomfort associated with these swabs. Since the saliva sample is self-collected under the observation of a healthcare professional, it could also potentially lower the risk posed to healthcare workers responsible for sample collection.

Are there different types of COVID-19 diagnostic tests?

There are 2 different types of COVID-19 diagnostic tests -- molecular tests and antigen tests. Molecular tests detect the virus that causes COVID-19, SARS-CoV-2. Antigen tests detect specific proteins made by the virus.

What kind of sample is used to test for COVID-19?

Swab samples use a swab (similar to a long Q-Tip) to collect a sample from the nose or throat. The types of samples include:

•Anterior Nares (Nasal) – takes a sample from just inside the nostrils
•Mid-turbinate – takes a sample from further up inside the nose
•Nasopharyngeal – takes a sample from deep inside the nose, reaching the back of the throat
•Oropharyngeal – takes a sample from the middle part of the throat (pharynx) just beyond the mouth

Saliva samples are collected by spitting into a tube rather than using a nose or throat swab.

Blood samples are only used to test for antibodies and not to diagnose COVID-19. Venous blood samples are typically collected at a doctor’s office or clinic. Some antibody tests use blood from a finger stick.

How long can you test positive for COVID-19?

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People who have recovered from COVID-19 can continue to test positive for up to 3 months after their infection.

Can patients who have recovered from COVID-19 continue to have detectable SARS-CoV-2 RNA in upper respiratory specimens?

• Patients who have recovered from COVID-19 can continue to have detectable SARS-CoV-2 RNA in upper respiratory specimens for up to 3 months after illness onset in concentrations considerably lower than during illness; however, replication-competent virus has not been reliably recovered and infectiousness is unlikely.

Can COVID-19 antigen tests be false positive?

Despite the high specificity of antigen tests, false positive results will occur, especially when used in communities where the prevalence of infection is low – a circumstance that is true for all in vitro diagnostic tests.

What does a negative SARS-CoV-2 antibody test mean?

A negative result on a SARS-CoV-2 antibody test means antibodies to the virus were not detected in your sample. It could mean:
• You have not been infected with COVID-19 previously.
• You had COVID-19 in the past but you did not develop or have not yet developed detectable antibodies.

How long should I wait to get tested for COVID-19 after being exposed if I am fully vaccinated?

- If you have been fully vaccinated and around someone who has COVID-19 (close contact), you do not need to stay away from others (quarantine), or be restricted from work unless you develop COVID-like symptoms. We recommend that you get tested 3-5 days after your last exposure to someone with COVID-19.

What does it mean if I have a negative rapid test result?

What does it mean if I have a negative rapid test result? A negative test result means that proteins from the virus that causes COVID-19 were not found in your sample. It is possible for this test to give a negative result that is incorrect (false negative).

What does a negative COVID-19 antigen test result mean in asymptomatic persons?

Negative test results using a viral test (NAAT or antigen) in asymptomatic persons with recent known or suspected exposure suggest no current evidence of infection. These results represent a snapshot of the time around specimen collection and could change if tested again in one or more days.

When are antigen tests the better option to screen for COVID-19?

The clinical performance of diagnostic tests largely depends on the circumstances in which they are used. Both antigen tests and NAATs perform best if the person is tested when their viral load is generally highest. Because antigen tests perform best in symptomatic people and within a certain number of days since symptom onset, antigen tests are used frequently on people who are symptomatic. Antigen tests also may be informative in diagnostic testing situations in which the person has a known exposure to a person with COVID-19.

How long does it take to get results for COVID-19 antigen tests?

Antigen tests are relatively inexpensive, and most can be used at the point of care. Most of the currently authorized tests return results in approximately 15–30 minutes.

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