This Is Exactly When You Should Get Tested for Coronavirus
The timing of your COVID-19 test is crucial for getting an accurate result.
Now that coronavirus testing has become widely accessible in the United States, many people are taking advantage of that fact. But while testing administration has been streamlined, the tests themselves can still be imprecise. To optimize your COVID-19 test and truly find out whether or not you have the virus, you'll want to make sure you get tested on the day you are most likely to receive an accurate reading.
According to a recent study published in the Annals of Internal Medicine, tests are returning an alarming amount of false negatives. The study found that the percentage of accurate results was dependent on when patients went to get tested. The majority of false negatives were attributed to the test being taken either too early or too late. Researchers found that the probability of a false negative is considerably lower one to three days after the onset of symptoms.
The study found that on the day of symptom onset, "the median false-negative rate was 38 percent." This percentage "decreased to 20 percent three days after symptom onset." This window between one to three days of experiencing symptoms is when you are most likely to receive accurate test results. If you believe you have contracted COVID-19, but have yet to experience any symptoms, don't rush to get a test right away.
The study found that the day you become infected, the probability of a false-negative result is about 100 percent. After four days of infection, the potential for a false-negative is still as high as 67 percent. So getting tested before you experience symptoms (which usually occurs five to seven days after infection) could result in inaccurate results. However, waiting too long to get tested could also lead to a false negative. If you get tested a week after you first notice symptoms, the probability of a false-negative spikes back up to 66 percent, according to the study.
For more on the testing process, check out The CDC's Major Coronavirus Testing Mistake That May Affect You.