Medical Necessity Determination for Definitive Drug Testing

Rationale for Medical Necessity

• The Centers for Disease Control and Prevention recommends definitive testing when a presumptive test was inconclusive or inconsistent, or when a presumptive test was positive for a prescription drug that wasn't prescribed to the patient, which is relevant for patients with substance use disorders and complex medication regimens 1
• Definitive testing is necessary to determine whether a patient is taking prescribed benzodiazepines appropriately, whether non-prescribed benzodiazepines are being used, or whether this represents a documentation error, particularly in patients with severe substance use disorders and psychiatric comorbidities 1
• The American College of Obstetricians and Gynecologists, as referenced in the American Journal of Obstetrics and Gynecology, suggests that medication prescribing decisions for controlled substances should be informed by definitive testing results, which is crucial for patients with active substance use disorder and complex medication regimens 2
• Confirmatory testing using methods like gas chromatography-mass spectrometry is the standard approach to resolve inconsistent immunoassay results, as immunoassays have known limitations including cross-reactivity and inability to differentiate specific benzodiazepines, as noted in the American Journal of Obstetrics and Gynecology 2, 3
• The Centers for Disease Control and Prevention emphasizes that clinicians should not test for substances for which results would not affect patient management, but in scenarios like this, the results directly inform medication prescribing decisions, treatment intensity, and safety interventions, including naloxone provision 1, 2

Definitive Drug Testing for Opioid Dependence

Medical Necessity Criteria for Definitive Testing

• Definitive drug testing should only be used in specific clinical scenarios, such as when a presumptive test is not commercially available for the specific drug, according to the American Academy of Pediatrics 4
• The Centers for Disease Control and Prevention recommends that definitive testing should be used when a presumptive test was negative for prescribed medications with abuse potential but the provider expected it to be positive, when a presumptive test was positive for a prescription drug that wasn't prescribed to the patient, when a presumptive test was inconclusive or inconsistent, or when a presumptive test was positive for an illegal drug and the patient disputes the results 5

Appropriate Use of Drug Testing in Substance Use Disorder Treatment

• The American Academy of Pediatrics suggests that drug testing in substance use disorder treatment should be used as an adjunct to clinical assessment, not as a standalone monitoring tool, and limited to testing for substances that would affect patient management 6, 7
• The Centers for Disease Control and Prevention recommends that drug testing should be restricted to confirmatory testing only when results can reasonably be expected to affect patient management 5, 8

Clinical Implications and Best Practices

• Clinicians should have a plan for responding to unexpected results before ordering drug tests, according to the Centers for Disease Control and Prevention 5, 8
• Discussion with patients about unexpected results can sometimes obviate the need for expensive confirmatory testing, as noted by the Centers for Disease Control and Prevention 5, 8