gold standard, reference test
The reference standard is the test, combination of tests, or procedure that is considered the best available method of categorising participants in a study of diagnostic test accuracy as having or not having a target condition.
Evaluations of diagnostic test accuracy require a comparison between the diagnostic test being evaluated (e.g. a rapid diagnostic test for malaria), which is referred to as the index test, and a reference standard used to categorise participants as having or not having the target condition (e.g. microscopy for malaria).
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