false negative

false negative

n.

A negative test result when the attribute for which the subject is being tested actually exists in that subject.

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false-nega·tive adj.

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False negative

Test results showing no problem when one exists.

Mentioned in: Stress Test

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false negative,

an incorrect result of a diagnostic test or procedure that falsely indicates the absence of a finding, condition, or disease. The rate of occurrence of false-negative results varies with the diagnostic accuracy and specificity of the test or procedure. As the accuracy and specificity of a test increase, the rate of false-negatives decreases. Certain tests are known to yield false negative results at a certain rate; in all tests a small number will occur by chance alone. False-negative results are more common than false-positive results, because the person conducting the test is more likely to fail to observe a finding than to imagine seeing something that does not exist. Compare false positive.

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false

said of diseases or plants that have a superficial resemblance to another plant or disease.

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false acacia

see robinia pseudoacacia.

false blackleg

cellulitis and myositis caused by Clostridium septicum and C. novyi. More commonly called malignant edema. Characterized by high fever, severe toxemia and local swelling around a wound with subsequent local gangrene and a high mortality rate.

false blusher

see amanitapantherina—a mushroom.

false buckbush

see gyrostemonaustralasicus.

false bursa

see hygroma.

false castor oil plant

daturastramonium, D. ferox.

false columnaris disease

similar to columnaris disease but caused by infection with the bacteria Cytophaga johnsonae. Characterized by skin erosion especially at the fins and jaws.

false distemper

a disease of horses with some similarity to strangles. See pectoral abscess.

false garlic

alliumvineale.

false gid

see oestrusovis.

false hellebore

veratrumcalifornicum, V. viride.

false indigo

see baptisia leucantha.

false joint

a fracture in a long bone that does not heal; the ends callus over and there is mobility at the point.

false layer

a hen with all the appearances and the behavior of a laying hen but which does not lay any eggs. There is a defect in ovum entrapment and the eggs are discharged into the peritoneal cavity although egg peritonitis is not apparent.

false lupine

thermopsismontana, T. rhombifolia.

false negative

when the result of a test in a patient is negative when the disease or condition which is the subject of the search is present.

false positive

see false-positive.

false quarter

a condition of the horse's hoof in which a serious injury to the coronet causes an overgrowth of horn which overlaps the normal wall.

false scorpions

members of the order Pseudoscorpiones. Nonvenomous arachnids called also book scorpions.

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false negative

Diagnostic medicine A test result–eg, Pap smear, mammography, from a Pt who has a particular disease, which is negative or does not detect the presence of an analyte that is usually abnormal in the disease of interest. See Four-cell diagnostic matrix, Cf False positive NIHspeak An active substance or result incorrectly identified as negative by an assay or test.