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Presumptive and definitive clinical drug testing solutions

Quest agrees with the CDC and multiple other organizations that clinical drug monitoring is the standard of care when controlled substances are prescribed. A consistent drug testing protocol to monitor medication adherence is essential to help ensure patient compliance and to identify harmful drug interactions, misuse, abuse, and diversion.

There are two main types of drug monitoring tests: presumptive and definitive. Testing can be performed on the same specimen for patient and provider convenience. Presumptive drug testing is a screen that is typically done with point-of-care (POC) devices that are usually quick and inexpensive, but results require confirmation via definitive testing. Definitive drug testing identifies specific substances (i.e., drugs, metabolites) and is conducted with highly sensitive clinical laboratory methods. Definitive drug testing can be used to confirm presumptive positive test results.

Presumptive drug tests

Presumptive drug tests are initial screens used to identify possible use or non-use of a drug or a drug class and to quickly rule out multiple drug classes before conducting definitive testing.

  • Cost less than definitive tests and may produce results faster, but they have higher cutoff values 
  • Do not identify drugs/metabolites and results are reported qualitatively (negative or positive)
  • Often have decreased sensitivity and specificity when compared to definitive testing, which leads to false-negative and false-positive results
  • Require definitive mass spectrometry to identify drug/metabolite present

Definitive drug tests

Definitive drug tests are used to identify specific drugs/metabolites present. Definitive testing has high sensitivity and is used to confirm or refute presumptive test results or for testing where presumptive tests are not available and reduces the occurrence of false-positive/false-negative results.

  • Performed with advanced laboratory technologies, definitive tests are more accurate than presumptive tests as they detect at a lower concentration. They can identify patterns of misuse presumptive tests might miss.
  • Used to identify specific substances or metabolites that are not detected by presumptive methods, including gabapentin, pregabalin, tapentadol, tramadol, synthetic cannabinoids, and other synthetic/analog drugs.
  • Used when a definitive concentration of a drug is needed to guide management (e.g., discontinuation of THC use according to a treatment plan).
  • Drugs/metabolites can be reported as either the name (qualitative) or the name and concentration (quantitative).

Best practices for using presumptive and definitive drug testing

In general, best practices include presumptive testing with confirmation of unexpected positives or negatives with definitive testing, as well as direct-to-definitive testing when a presumptive test for a specific drug is not available.

  • Presumptive test panels can provide initial results that can be confirmed with definitive testing
  • Definitive drug testing is used to identify a specific drug that is inadequately detected by a presumptive test
  • Definitive drug testing is used to identify specific drugs or drug metabolites
  • Definitive drug testing is used when a presumptive test for a drug or drug class is not available

The Quest Diagnostics Health Trends® report, Drug Misuse in America 2021, reveals the importance of definitive drug testing

Download the full report

Definitive drug testing panels

When definitive testing is needed, our definitive drug testing panels have you covered. Panels include the most commonly ordered substances and use a smaller urine specimen—and with a fast turnaround. Results for all substances are delivered in one consolidated report, so you can take actions quickly to optimize patient care.

When you choose Quest, you’ve chosen one lab that can help you with all your testing needs.

Contact us to learn how we can meet your needs at every stage of patient care.

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Our toxicology experts are here for you

Whether you want to discuss test selection, sample requirements, results interpretation, or to schedule an in-depth call for more complex questions, our team is available via phone at

1.877.40.RXTOX (1.877.407.9869)

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