What is reflex testing and when is it used?

What is reflex testing and when is it used?

• A. Automatic follow-up testing of additional analytes or using alternative methods based on initial screening results.
• B. Testing only when the patient requests.
• C. Rechecking the same result with the same method.
• D. Only used for pH verification.

Answer: (B)

Reflex testing is automatic follow-up testing that is triggered by the results of an initial screen. Instead of waiting for a clinician or patient to request another test, the lab proceeds to confirm or broaden the finding right after the screening result, often by testing for additional drugs or using a different, more specific method.

This approach improves accuracy by confirming true positives and reducing false positives, and it speeds up decision-making because confirmation starts without delay after a positive or equivocal screen. In drug testing, a common pattern is to perform a confirmatory test (such as GC-MS or LC-MS/MS) when the initial immunoassay screen is positive, or to reflex to additional analytes if the screen suggests possible results for certain drug classes.

The idea described as testing only when the patient requests is not reflex testing, since reflex testing is lab-initiated based on screening results. Rechecking the same result with the same method is not reflex testing either, as reflex involves a different test or additional targets. And reflex testing isn’t limited to pH verification; it’s a practice used to confirm or extend drug testing results.