A<unk>  <unk>  is a measure of how far an individual test result deviates from the<unk> .<unk>  is commonly used to report the results of medical screening tests, particularly where the results of the individual tests are highly variable.<unk>  was originally used as a method to normalize data from participating laboratories of Alpha-fetoprotein (AFP) so that individual test results could be compared. 35 years later, it is the established standard for reporting maternal serum screening results. An<unk>  for a test result for a patient can be determined by the following: : As an example, Alpha-fetoprotein (AFP) testing is used to screen for a neural tube defect (NTD) during the second trimester of pregnancy. If the<unk>  AFP result at 16 weeks of gestation is 30 ng/mL and a pregnant woman's AFP result at that same gestational age is 60 ng/mL, then her<unk>  is equal to 60/30 = 2.0. In other words, her AFP result is 2 times higher than<unk> .
Multiple of the median
Relative value unit
Absolute threshold
Equivalent dose
Form constant
Threshold limit value
Indicative limit value
Minimal important difference