false positive

noun

plural false positives

: a person or test result that is incorrectly classified as positive (as for the presence of a health condition) because of imperfect testing methods or procedures

A false positive—a test result indicative of disease that isn't actually present—can trigger a chain reaction of worry, further tests, and even unnecessary treatment.

—Harvard Health Letter

The quarantine could be lifted early if the lab confirms that the case was a false positive.

—Kathleen Moore

Perhaps more important, polygraph tests are notoriously unreliable. Scientists are understandably concerned about false positive results …

—Chemical & Engineering News

—often hyphenated when used before another noun

The technology could improve a radiologist's ability to detect breast cancers and it could lower the number of false-positive results …

—Laurie Tarken

compare false negative

Examples of false positive in a Sentence

Recent Examples on the Web

Given that heavy smokers over 50 are at 64 to 111 times greater risk of lung cancer compared to the general population, the risk of false positives is greatly overshadowed by the benefits of early diagnosis. —Doru Paul, Verywell Health, 15 Nov. 2023

Cameras connected to hot list databases that haven’t been updated have produced false positive hits, the Texas A&M Transportation Institute reported in a 2021 study. —Myah Taylor, Dallas News, 5 June 2023

Say a detection tool has a 1 percent false positive rate—an optimistic assumption. —Christopher Beam, WIRED, 14 Sep. 2023

Read on for a breakdown of NIPTs, when NIPT false positives are more likely, and how to make the best decision for you. —​wendy Wisner, Parents, 10 Aug. 2023

In situations where probable cause is required for search warrants or arrests, false positives could lead to unnecessary infringements on individuals' rights. —Amber Smith, Discover Magazine, 27 June 2023

If, on the other hand, a test returns positive and the value rises, a false positive is less likely. —Mara Buchbinder, STAT, 29 Oct. 2023

But officers were worried the dog’s fatigue yielded a false positive. —Nicole Asbury, Washington Post, 25 Oct. 2023

One bugaboo for universities has been false positives. —IEEE Spectrum, 1 Sep. 2023

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Word History

First Known Use

1912, in the meaning defined above

Medical Definition

false positive

noun

: a person or test result that is incorrectly classified as positive (as for the presence of a health condition) because of imperfect testing methods or procedures

Another problem with the test … is that it also produces a number of false positives; that is, a number of neonates with elevated trypsin levels the first time they are tested are found not to have elevated levels on the second test.

—The Journal of the American Medical Association

The urine dipstick test for protein can give false positive results when various pharmacologic agents and gross hematuria are present or when urine pH is high …

—Biff F. Palmer, Scientific American Medicine

—often hyphenated when used before another noun

… false-positive results that led healthy women to have unnecessary surgery.

—Denise Grady, The New York Times

The test can give false-positive readings, however, and it triggers a follow-up colonoscopy in 4% to 10% of cases.

—Marilyn Chase, The Wall Street Journal

compare false negative