Non-negative result

A non-negative result is the correct term for a screening test that reads at or above the cutoff before confirmatory testing has been performed.

Laboratories and regulated programs avoid calling a screen positive because immunoassays detect a class of compounds and can respond to substances other than the target. The sample is sent for confirmation by mass spectrometry, which identifies the specific compound and its concentration. Only a confirmed result, reviewed under the program's procedures, is reported as positive.

The distinction matters for anyone using cannabinoid products, because the screening stage and the confirmation stage answer different questions: the first asks whether something in the class may be present, the second asks exactly what and how much. A non-negative screen that confirmation does not support is a false positive; one that confirmation supports is a positive regardless of the source of the compound. Understanding the two stages helps a person respond accurately if asked about a result.