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U.S. Department of Health and Human Services

Medical Devices

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Glossary

Accuracy:  A measure of agreement between a test result and an accepted reference value. Example: If you have a standardized reference material at a known value (such as 180 mg/dl of cholesterol), accuracy measures how close the result of the test you are using will get to the known value. You may have a test that is very precise yet very inaccurate, which would be the case if your device measures 180 mg/dl of cholesterol reproducibly as 240 mg/dl.

Analyte:The part of the sample that the test is designed to find or measure.  Example: A home pregnancy test measures human chorionic gonadotropin (hCG) in urine. The analyte is hCG.

Approved Test: A test that has been approved by FDA, based on the manufacturer's data showing that it is safe and effective for its intended use.
For a new type of test, or for a test that presents higher risk to the patient, the manufacturer performs studies to show that the test does what it claims to do and does not present any unreasonable risk. The manufacturer submits the results in a "premarket approval application" that FDA reviews. If FDA approves the application, the manufacturer can begin selling the test.

Cleared Test: A test that has been cleared by FDA, based on the manufacturer's data showing that it is similar to other tests that are already being sold. For a test that is similar to others already on the market and that is considered to have low risk to the user, manufacturers submit information to show that the test performs similarly to the other tests. The manufacturer submits the results in a "premarket notification" that FDA reviews. If FDA determines that the test is substantially equivalent to another test, the manufacturer can begin selling the test.

Exempt Test: A test that is considered to have such low risk to the patient that FDA does not require manufacturers to submit any premarket approval application or notification.

False Negative: A test result that incorrectly says the analyte, disease, or condition is not present when it actually is present. False negatives can be due to human error, test error, or substances in the sample that interfere with the test.
Example: A woman who is pregnant receives a test result saying that she is not pregnant.

False Positive: A test result that incorrectly says the analyte, disease, or condition is present when it is actually not present. False positives can be due to human error, test error, or substances in the sample that interfere with the test.
Example: A woman who is not pregnant woman receives a test result saying she is pregnant.

Indications For Use: A description of why a patient would use a certain test.

Intended Use: A description of what the manufacturer intended to measure with a certain test.

In Vitro Diagnostic Test: A medical test that analyzes body samples, such as blood, urine, stool, or saliva, for specific components or analytes.

Label: Written material and instructions that accompany the medical test. Labeling includes the writing on the outside of the box as well as instructions packaged with the test.

Over-The-Counter(OTC) Tests: Tests that can be purchased and used by anyone at home. These do not require a doctor's prescription.  If manufacturers intend to sell their test kits over the counter, they must demonstrate that untrained lay persons can perform the tests and get good results.

Package Insert: Information about the test and/or instructions that come inside the box or package.

Qualitative Test: A test that gives results in terms of negative or positive.
Example: Pregnancy tests, ovulation tests, and drugs of abuse detection tests indicate whether or not the person has the condition.

Quantitative Test: A tests that gives results in terms of numbers.
Example: Glucose meters indicate how much glucose is present in the sample.

Screening Test: An initial or preliminary test. Screening tests do not tell you if you definitely have a disease or condition. Rather, positive results indicate that you may need additional tests or a doctor's evaluation to see if you have a particular disease or condition.