What is the term for the range of normal values used to interpret laboratory tests?

What is the term for the range of normal values used to interpret laboratory tests?

• A. Profile
• B. Reference range
• C. In vivo
• D. Laboratory test

Answer: (B)

The range of normal values used to interpret lab tests is called the reference range. Labs establish this by examining results from healthy individuals and defining an interval that covers the expected values, typically about 95% of those results. This creates lower and upper limits that clinicians use to judge whether a patient’s result falls within normal limits. Values within the reference range are usually considered normal, while values outside may indicate an abnormal finding—though interpretation always depends on the patient’s context, including age, sex, and the specific test method. Some tests have separate reference ranges for different ages or sexes, and some laboratories define ranges as a reference interval rather than a fixed range. Other terms don’t describe this concept: a profile is a set of tests run together, not the normal-value range; in vivo refers to processes inside the living body; a laboratory test is the procedure itself, not the range used to interpret results.

The range of normal values used to interpret lab tests is called the reference range. Labs establish this by examining results from healthy individuals and defining an interval that covers the expected values, typically about 95% of those results. This creates lower and upper limits that clinicians use to judge whether a patient’s result falls within normal limits. Values within the reference range are usually considered normal, while values outside may indicate an abnormal finding—though interpretation always depends on the patient’s context, including age, sex, and the specific test method. Some tests have separate reference ranges for different ages or sexes, and some laboratories define ranges as a reference interval rather than a fixed range.

Other terms don’t describe this concept: a profile is a set of tests run together, not the normal-value range; in vivo refers to processes inside the living body; a laboratory test is the procedure itself, not the range used to interpret results.