A result should be interpreted in layers. First determine what document you have; then identify the method, analyte, cutoff, review status, and decision the result can actually support.
Step 1: Classify the report
Is it a home screen, point-of-care screen, laboratory screen, confirmation report, MRO-verified workplace result, clinical chart entry, or forensic toxicology opinion? Words such as “nonnegative,” “presumptive,” “confirmed,” and “verified” are not interchangeable.
Step 2: Verify identity and specimen
Check the tested person’s identifiers, collection date and time, specimen type, accession or custody number, collector, laboratory, and report status. A corrected or amended report should supersede an earlier version.
Step 3: Read the analyte and cutoff
Identify the exact drug or metabolite, screening cutoff, confirmation cutoff, concentration if reported, and units. Do not assume a class screen identifies every member of the class.
Step 4: Separate analytical and medical questions
The laboratory asks whether an analyte met reporting criteria. A clinician or MRO may ask whether medication or another legitimate explanation exists. A policy maker or court asks what the verified result means under its rules. Each step has a different role.
Step 5: Check specimen validity
Review creatinine, specific gravity, pH, oxidants, or program classifications when available. A dilute, invalid, adulterated, or substituted result has defined implications and may require recollection or review.
Step 6: Limit the conclusion
A positive urine result commonly supports detection above a cutoff; it usually does not establish exact dose, time, impairment, addiction, or intent. A negative result does not prove no use. Explain only what the method supports.
Step 7: Choose the next action
- For a presumptive result, obtain required confirmation.
- For an unexpected clinical result, discuss timing, medications, panel coverage, and repeat or definitive testing.
- For a workplace result, complete MRO review and follow the written policy.
- For a legal or sports result, preserve the notice and deadlines for split or B-sample testing and appeal.
Urgent safety
A laboratory result is only one part of an emergency assessment. If a person is unresponsive, having trouble breathing, severely confused, or otherwise in danger, seek emergency care rather than waiting for a drug-test interpretation.
Related: Understanding Drug-Test Results, Reviewing a Disputed Result, and Decision Guides.