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

Once the organization is comfortable that the virtual patch will not cause any false positives, the security control enforcing the virtual patch can be placed in a more restrictive prevention mode. —Austin Gadient, Forbes, 13 Dec. 2024

Ephedrine and phenylephrine, medications for low blood pressure that are commonly prescribed during C-sections, have caused false positives for meth. —Shoshana Walter, USA TODAY, 11 Dec. 2024

Even so, Patel acknowledged that the algorithm isn’t 100 percent accurate and that false positives and negatives were possible; Oura didn’t provide specific accuracy data. —Victoria Song, The Verge, 5 Dec. 2024

But the challenge, Cole says, is in refining mobile monitoring tools to reduce false positives. —Lily Hay Newman, WIRED, 4 Dec. 2024

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