Understanding Drug Test Cutoff Levels: How to Read a PharmChek® Lab Report

What counts as "positive" on a drug test?

That question carries real consequences. Court orders. Probation status. Recovery progress.

Yet for judges, probation officers, and treatment providers, the answer isn't always straightforward. Especially when a PharmChek® Sweat Patch comes back positive but a urine test doesn't.

Let’s break it down.

This article explains cutoff levels in plain terms, shows you how to read a PharmChek® report with confidence, and shares what those numbers actually mean in legal and clinical practice.

What Is a Drug Test Cutoff Level?

Cutoff level: The amount of drug that must be present in a specimen for the test result to be reported as positive.

Drug testing with PharmChek® involves two thresholds. The first is a screening cutoff, which uses immunoassay to flag presumptive positives. Any presumptive positive is then confirmed using LC-MS/MS at the confirmation cutoff level.

A result is only reported as a confirmed positive if the analyte exceeds the confirmation threshold. For some drugs, confirmation also requires the presence of a corresponding metabolite, such as amphetamine when methamphetamine is detected. For others, such as THC, confirmation is based solely on the parent drug.

A result below the cutoff is reported as negative.

Understanding these thresholds is essential for fairness in the courtroom. A participant shouldn't face sanctions based on misinterpreted trace results, and judges must base decisions on clear, defensible science, not guesswork.

Cutoff vs. Detection: What’s the Difference?

Detection is straightforward, indicating that a drug is present in the sample.

Cutoff determines whether detection matters, as it sets the minimum amount of drug that must be present to trigger a positive result. Cutoff levels help filter out incidental contact or environmental exposure that might otherwise lead to unfair sanctions. They're essential for drawing a line between trace contamination and actual substance use.

Think of detection as the raw signal. Cutoff is the filter that tells you when to act.

As Judge Greg Pinski explained at PharmChem’s RISE25 presentation:

Why Cutoff Levels Exist

Cutoff levels serve a critical role:

• Avoid false positives
• Ensure forensic reliability
• Set consistent reporting thresholds across labs

Cutoff levels help courts distinguish between trace contact and actual use. And they vary by specimen type.

To make informed rulings, professionals need to understand both the logic and limitations of those numbers.

Sweat Patch vs. Urine Test: Cutoff Levels Explained

Sweat testing and urine testing serve very different purposes, and understanding why cutoff levels vary between the two is essential for fair interpretation.

Unlike urine testing, which provides a short-term snapshot, sweat testing offers a broader view. The PharmChek® Sweat Patch is designed to detect drug use over an extended period, generally 7 to 10 days, without requiring observed collection or multiple office visits.

This PharmChek® comparison highlights a few key distinctions:

• Detection window: Sweat captures continuous use over a week or more. Urine reflects only the past 1–3 days.
• Tamper resistance: The patch is applied directly to the skin and resists dilution or substitution, unlike urine.
• Specimen volume: Urine samples provide more liquid volume, allowing for higher cutoff thresholds. Sweat has a smaller volume, so lower cutoffs are necessary.
• Participant experience: Urine collection often requires same-gender observation. Sweat testing does not.

These differences impact how and when substances are detected. Sweat testing is far less prone to manipulation, supports trauma-informed care, and reduces logistical burdens for participants and providers alike.

Sweat and urine aren't equal.

Drug concentrations in sweat are much lower because the sample is smaller.

Kerri Wagner of PharmChem explains:

This isn't a weakness—it's a design difference. PharmChek® reflects a cumulative exposure over time, not just a snapshot.

Common Cutoff Levels

Can cutoff levels affect drug test results?

Yes. Cutoff levels determine whether a detected substance meets the threshold to be reported as positive. This is why a person may test negative for drugs on a urine test but positive on a sweat patch.

The chart below compares standard cutoff levels used in PharmChek® Sweat Patch testing with typical cutoff levels used in urine drug testing. While the urine cutoff values below reflect federal guidelines (such as those set by SAMHSA), actual thresholds can vary depending on the lab, testing panel, or specific product used. The urine cutoff numbers presented are examples only:

How to Interpret a PharmChek® Sweat Patch Lab Report

Reading a report isn't just about spotting "positive" or "negative." It’s about understanding what those terms mean, why they matter, and communicating that clearly to courts, teams, and participants.

Definitions to Know

What is a Parent Drug?

A parent drug is the original compound that was ingested (e.g., methamphetamine).

What is a Metabolite?

A metabolite is the by-product your body creates as it breaks down the drug (e.g., amphetamine from meth).

What is LC-MS/MS?

LC-MS/MS is short for liquid chromatography-tandem mass spectrometry. It’s the platinum standard for confirmatory drug testing, used to identify exact molecules, eliminate false positives, and provide legally admissible results.

5-Step Lab Report Walkthrough

1. Start with the Result Summary

• Look at each drug class and whether it’s marked positive or negative.

2. Check for Confirmed Positives

• A confirmed positive result means that both the parent drug and its metabolite exceeded the cutoff thresholds and were validated by LC-MS/MS.

3. Interpret "Present" vs "Positive"

• “Present” means that LC-MS/MS detected the drug in the specimen (i.e., the analyte was present within the method's limit of detection), but the result did not meet the criteria to be reported as a confirmed positive.
• “Positive” means the drug exceeded the threshold for a positive result.
• These categories help you understand exposure, but only confirmed positives should guide legal or disciplinary decisions.

4. Read Notes on Metabolites

• Methamphetamine, present with amphetamine, confirms ingestion.
• Methamphetamine without amphetamine could suggest environmental exposure, because no amphetamine means there is no metabolite, which means there was no ingestion.
  
  As Ed Gilligan, Director of Juvenile Court Services in Yuma, Arizona said at RISE25, "Toxicologist testimony at a due process hearing clarified that environmental meth exposure gives meth-positive but amphetamine-negative. Actual ingestion shows both."

5. Don’t Rely on Concentration Numbers Alone:

• At RISE25, Judge Pinski emphasized: “From a best-practice standpoint, we need to eliminate concentration talk and look only at the qualitative result: positive or negative.”
• Raw nanogram values can be misleading and should not be used to justify sanctions. The cutoff system exists to provide a fair and scientifically valid threshold.

Common Questions About Interpreting Results

What does it mean when a lab report uses the word “present”?

If a PharmChek® report includes the word “present,” it means that LC-MS/MS detected the drug and the result has been confirmed positive for that substance. You will only see the word “present” in the context of a confirmed positive report. If the result is negative, the report will simply state “negative,” even if trace amounts were detected below the reporting threshold.

Why is confirmation important?

Because confirmation ensures results are verified using LC-MS/MS, meeting standards for forensic and legal admissibility. Only results marked as "positive" on the final report, meaning they exceeded the confirmation cutoff, should be treated as evidence of drug use.

Bonus Tip: Use the Report as an Educational Tool

Reports shouldn’t be limited to staff interpretation.

Educate your participants. Help them understand why they’re getting a particular sanction or why results appear inconsistent.

Greater understanding often leads to greater buy-in and long-term compliance.

When Positive Doesn’t Mean New Use

Why would a sweat patch test positive and a urine test be negative?

Because sweat and urine have different detection windows and cutoff levels. A sweat patch may detect cumulative drug use over a week, while a urine test captures only recent use within 1–3 days.

In other words, drug use timelines matter, especially with PharmChek®, which covers 7–10 days of continuous wear.

A positive result doesn’t mean use occurred yesterday. It means that drug use happened during the wear period.

That’s a key advantage of sweat testing:

"The patch replaces a 72-hour snapshot with a two-week picture, giving a more realistic view of sobriety," says Judge Greg Pinski.

This long window can detect:

• Missed doses during weekends
• Strategic chipping or micro-dosing
• Attempts to dilute or evade urine testing

Micro-Dosing in Action

Judge Pinski says, "A urine test might cut meth at 20 ng/mL while a patch cuts at 5 ng/mL. Participants may micro-dose to beat urine, but the patch still flags the use."

This insight is especially useful in early recovery, when a participant’s cravings are high and motivation may be low.

PharmChek® helps the team stay a step ahead.

Defensibility in the Courtroom

PharmChek® reports are court-admissible.

LC-MS/MS confirmation means results are scientifically sound and legally defensible. This platinum standard ensures that every confirmed positive has been validated through precise molecular identification, ruling out false positives from over-the-counter or environmental exposure.

In U.S. v. Pangelinan (District of Guam, 2024), the court upheld a PharmChek® result even when urine tests were negative.

Why?

Because PharmChek®:

• Detected methamphetamine and amphetamine
• Used LC-MS/MS for confirmation
• Reflected a longer detection window

That kind of evidence holds up. And it’s not an isolated case.

Judge Sandra Day O’Connor, writing for the 8th Circuit, cited the sweat patch as:

Legal defensibility matters most when liberty is at stake.

Trust the science.

Educate the court.

Focus on presence, not numbers.

Why This Matters for Equity and Recovery

Traditional urine testing can retraumatize participants.

As Gilligan shared, the experience of observed collection, especially for minors or justice-involved individuals, is not only awkward but also potentially harmful. He recalled the lasting impact of watching a probationer provide a urine sample under observation early in his career, noting:

Urine testing often requires participants to stand in a bathroom with an observer, pants at their knees, and be watched closely as they provide a sample. For individuals with trauma histories, that level of exposure and surveillance can trigger deep anxiety or emotional distress.

This isn’t just uncomfortable. It can directly impact compliance, engagement, and trust in the system.

Frequent check-ins at public drug labs, exposure to high-risk peers, and the humiliation of observed urination all compound the stress. And even after all that, manipulation remains common with urine testing.

Sweat testing with PharmChek® removes much of that burden.

The sweat patch offers:

• Continuous monitoring without direct observation
• Less participant burden (no frequent travel)
• Trauma-informed options (especially for clients with sexual trauma)

As Judge Pinski emphasized:

The PharmChek® Sweat Patch is about outcomes, not punishment.

It can also build trust.

When participants understand the why behind the results—and see consistency in responses—they're more likely to stay engaged in treatment.

That’s how drug courts reduce recidivism, and that’s how we drive lasting change.

Know the Numbers, Then Look Beyond Them

Cutoff levels aren’t just lab values. They’re clinical decision tools.

Understanding them empowers you to:

• Defend results in court
• Educate participants
• Promote equity and recovery

Don’t just rely on the result.

Know what it means, know how to explain it, and know when to advocate for a more accurate, more humane form of drug monitoring.