--- title: "Blood Drug Screen: Accuracy & Reliability | AMH Nationwide" description: "Blood drug screen accuracy depends on certified lab methods, cutoff levels, and MRO review. Learn how false positives are ruled out. Call (877) 731-6362." author: "AMH Nationwide" date: "2026-08-27" tags: ["blood drug screen accuracy"] canonical: "https://amhnationwide.com/blood-drug-screen-accuracy/" last_updated: "2026-08-27" --- # Blood Drug Screen: Accuracy & Reliability | AMH Nationwide **By AMH Nationwide** | August 27, 2026 Blood drug screen accuracy depends on certified lab methods, cutoff levels, and MRO review. Learn how false positives are ruled out. Call (877) 731-6362. --- Blood drug screen accuracy is ensured through certified lab methodologies, strict cutoff levels, and review by a Medical Review Officer (MRO). Initial immunoassay screens are confirmed by advanced testing to rule out false positives. AMH Nationwide routes tests through five national lab networks for dependable results. Call (877) 731-6362. OVERVIEW ## What determines blood drug screen accuracy? Blood drug screen accuracy depends on several factors including the testing methods used, the cutoff levels for positive results, and the confirmation process. Initial screening uses immunoassays that are highly sensitive but can produce false positives. Confirmatory testing with techniques like gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS) is required to ensure reliability. AMH Nationwide directs all blood drug screens to one of five national lab networks: [Quest Diagnostics](https://www.questdiagnostics.com/), [LabCorp](https://www.labcorp.com/), Omega Labs, United States Drug Testing Labs, and ExperTox. These labs follow strict federal and industry guidelines to maintain consistent accuracy. TESTING PROCESS ## How does initial screening differ from confirmation testing in blood drug screens? Initial blood drug screens use immunoassay techniques that quickly detect the presence of drugs or metabolites in the blood. These tests are designed for high sensitivity to minimize missed positives but can yield false positives due to cross-reactivity. Confirmation testing uses more specific and sensitive methods such as GC-MS or LC-MS/MS. These tests identify and quantify the exact substance, eliminating false positives from the initial screen. Initial Screen: Immunoassay, fast, sensitive, potential false positives Confirmation Test: GC-MS or LC-MS/MS, specific, accurate, definitive results CUTOFF LEVELS ## What role do cutoff levels play in blood drug screen accuracy? Cutoff levels are set thresholds for drug concentration that determine whether a test result is positive or negative. They are established based on scientific research and regulatory guidelines to balance sensitivity and specificity. Using appropriate cutoff levels reduces false positives from incidental exposure or cross-reacting substances. Each drug panel has specific cutoff values that labs strictly adhere to during both screening and confirmation. | Drug Class | Typical Cutoff Level (ng/mL) | | --- | --- | | Amphetamines | 500 | | Cannabinoids (THC) | 1.5 | | Cocaine Metabolites | 150 | | Opiates | 2000 | | Phencyclidine (PCP) | 25 | LABORATORY STANDARDS ## How do certified lab methodologies ensure blood drug screen reliability? Certified laboratories follow stringent protocols including chain of custody, quality control, and validated testing methods to ensure reliable blood drug screen results. AMH Nationwide partners with labs certified by agencies such as CLIA and CAP. These labs use federally approved equipment and adhere to guidelines set by the Substance Abuse and Mental Health Services Administration ([SAMHSA](https://www.samhsa.gov/workplace/drug-testing)) and other regulatory bodies. This guarantees consistent accuracy and legal defensibility. ## Ensure Accurate Blood Drug Screen Results To schedule a blood drug screen with certified labs and MRO review, call (877) 731-6362. AMH Nationwide directs you to authorized collection sites nationwide. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) MRO REVIEW ## What is the role of the Medical Review Officer in blood drug screen accuracy? Every non-negative blood drug screen result undergoes review by a certified Medical Review Officer (MRO). The MRO evaluates the lab data and interviews the individual to determine if there is a legitimate medical explanation for the positive result. This process helps rule out false positives caused by prescription medications or other factors, ensuring that only verified positives are reported. The MRO’s review is a critical quality control step in the testing process. FALSE POSITIVES ## How are false positives ruled out in blood drug screens? False positives in blood drug screens are minimized by using confirmatory testing methods that specifically identify the drug compound. The initial screen’s immunoassay is prone to cross-reactivity with other substances, but confirmation tests like GC-MS or LC-MS/MS do not share this limitation. Additionally, the MRO review evaluates clinical and pharmaceutical history to exclude positives from legitimate medication use. Together, these steps ensure that positive results are accurate and reliable. AMH Reviewed & Maintained By AMH Nationwide Customer Service AMH Nationwide is BBB A+ accredited and routes every order through Quest Diagnostics, LabCorp, Omega Labs, United States Drug Testing Labs, or ExperTox, all of which use multiple lab certification agencies and standards such as SAMHSA-aligned laboratory protocols, the ANSI National Accreditation Board for forensic testing and calibration, the College of American Pathologists (CAP), and Clinical Laboratory Improvement Amendments (CLIA). Every non-negative screen is reviewed by a certified Medical Review Officer as part of standard processing before a result is released, and chain-of-custody documentation is maintained on every collection. This page does not constitute medical or legal advice. **Last updated:** July 2026 You May Also Need [Nail Drug TestingNo head or body hair available? A 5-panel fingernail test covers a similar look-back window.Learn more →](https://amhnationwide.com/5-panel-fingernail-drug-test/)[ChildGuard: Environmental ExposureConcerned about a child or loved one? ChildGuard screens for exposure to drugs in their environment.Learn more →](https://amhnationwide.com/5-panel-hair-drug-test-environmental-exposure-childguard/)[Shorten the Detection WindowShortened options like 30 and 60 day hair panels are also available, useful when a urine test’s 1-3 day window is too short.Learn more →](https://amhnationwide.com/30-day-hair-drug-test/)[Hair ETG Alcohol TestAlso need alcohol testing? The hair ETG test screens for alcohol use, and can be added to the same collection.Learn more →](https://amhnationwide.com/etg-and-peth/) Frequently Asked Questions ## Common Questions Yes, blood drug screens detect recent drug use because drugs remain in the bloodstream for a limited time, typically hours to a few days depending on the substance. Confirmation testing is necessary to eliminate false positives from the initial immunoassay screen by specifically identifying the drug using advanced techniques. All positive or non-negative blood drug screen results are reviewed by a certified Medical Review Officer to verify the accuracy and rule out legitimate medical explanations. Common substances tested include amphetamines, cannabinoids, cocaine metabolites, opiates, and phencyclidine (PCP), with cutoff levels established for each. AMH Nationwide provides the lab order and directs the requester to an authorized collection site within the five national lab networks. There is no online ordering. DOT-regulated safety-sensitive testing requires federally certified [urine](https://amhnationwide.com/urine-drug-testing/) testing under [49 CFR Part 40](https://www.transportation.gov/odapc/part40); blood drug screens are used primarily for non-DOT roles. Sources • [SAMHSA – Mandatory Guidelines for Federal Workplace Drug Testing Programs](https://www.samhsa.gov/workplace/drug-testing) • [U.S. DOT – 49 CFR Part 40 – Procedures for Transportation Workplace Drug and Alcohol Testing Programs](https://www.transportation.gov/odapc/part40) • [CDC – National Center for Health Statistics – Drug Use FastStats](https://www.cdc.gov/nchs/fastats/drug-use.htm) • [Quest Diagnostics – Employer Solutions, Hair Testing Methodology](https://www.questdiagnostics.com/) • [LabCorp – Occupational Testing Services](https://www.labcorp.com/) ## Ready to get started? AMH Nationwide provides the lab order and arranges collection nationwide. Every non-negative result reviewed by a certified Medical Review Officer. Call (877) 731-6362 or contact us. [Call (877) 731-6362](tel:+18777316362)[Contact Us](https://amhnationwide.com/contact-us/) --- **Need a drug, alcohol, HIV or STD test?** AMH Nationwide is a national lab testing agency operating since 2004, with more than 20,000 collection sites across the United States. Hair, urine, fingernail and blood testing, panels from 5 through 19, for individuals and employers. - Call: (877) 731-6377 - Find a collection site: https://amhnationwide.com/locations/ - Full page: https://amhnationwide.com/blood-drug-screen-accuracy/