How positive results are confirmed

Instant drug tests are designed to be fast and inexpensive. They do that job well, but they are screens, and screens can occasionally flag something that is not there or react to a legitimate medication. Laboratory confirmation is the safeguard. It uses more specific methods to identify exactly what is in a sample and how much.

Screening versus confirmation

The National Institute on Drug Abuse describes drug testing as a two stage process. An initial screen sorts samples into negative and presumptive positive. A more specific confirmation test then verifies the result. NIDA also cautions that a positive test does not by itself diagnose a substance use disorder, and that results should not be the sole basis for decisions about someone’s care (NIDA).

Two cutoffs, one sample

Confirmation tests are more precise, so they can use their own, often lower, cutoffs. Federal workplace guidelines show how this works. Under SAMHSA’s urine guidelines, a marijuana screen uses a 50 ng/mL cutoff and the confirmatory test uses 15 ng/mL; for cocaine, 150 ng/mL on the screen and 100 ng/mL on confirmation; for oxycodone, 100 ng/mL on both (SAMHSA, Federal Register 2023). For alcohol, Mayo Clinic Laboratories lists laboratory confirmation cutoffs of 250 ng/mL for EtG and 100 ng/mL for EtS (Mayo Clinic Laboratories).

Our program is not a federal workplace program, and our partner laboratories set their own validated methods and cutoffs. We will tell you what applies to your sample.

How confirmation works at Blackburn

1. The screen is presumptive positive. Your coordinator tells you right away and asks about medications, prescriptions and anything else that could explain the result.
2. The sample is sealed and documented. When needed, we complete chain of custody documentation that records who collected, sealed and handled the sample.
3. It goes to a partner laboratory. We work with partner laboratories for confirmation testing.
4. The laboratory reports back. The result either confirms the substance or rules the screen out.
5. We share it with the right people. Results go only to the people you have authorized in writing, and a coordinator explains what they mean.

Chain of custody, explained simply

Chain of custody is a paper trail. It shows that the sample tested in the laboratory is the same one you gave, and that no one could have swapped or altered it along the way. Courts, attorneys and some professional programs require it. Families usually do not. If you are not sure whether you need it, ask your attorney or program before your first test, and tell us. We can provide chain of custody documentation when needed. For legal matters, check with your attorney whether the court requires a specific vendor or format. Our guide explains what chain of custody means for a drug test.

When to ask for confirmation

• When a result will lead to a consequence, such as a legal report, a family decision or a change in care.
• When the person tested disputes the result.
• When a prescribed medication could explain the screen.
• When a low level EtG result could reflect incidental exposure, such as hand sanitizer or mouthwash, which Mayo Clinic Laboratories notes can produce detectable EtG (Mayo Clinic Laboratories).

Confirmation adds cost, which is one reason we do not send every sample to a laboratory. Your coordinator will explain when confirmation makes sense for your plan, and some plans, such as legal ones, confirm every positive.

After a confirmed positive

A confirmed result is information. What happens next matters more. The American Society of Addiction Medicine’s guidance on appropriate use of drug testing treats testing as a tool that supports care, not a replacement for it. That is how we see it too. Your coordinator can help you or your family think through next steps, from adjusting the testing plan to connecting with therapy, psychiatric care, sober living or one-on-one mentoring across Blackburn.

A positive result can bring up shame, fear or conflict. If anyone is in danger, call 911. If someone is thinking about suicide or in emotional crisis, call or text 988.

Where confirmation fits in your plan

Every test we offer can lead to confirmation: the 12 panel urine cup, the EtG alcohol test and the saliva test. For legal matters, see our page on court ordered and attorney referred testing.

Need more than testing?

Monitoring is the first step, not the last. If a result or a hard week tells you more help is needed, Blackburn can connect you to it.

• Therapy and psychiatry

  Assessment, therapy and psychiatric care at Blackburn Clinical Services.

  Visit Blackburn Clinical Services

• Sober living

  Structured sober living and sober apartments on the Westside through Blackburn Recovery Services.

  Visit Blackburn Recovery Services

• Mentoring

  One-on-one mentoring for accountability and structure, at work, at home and in daily life.

  Visit Blackburn Mentoring

• Scholarship help

  Treatment scholarships for people who need care and cannot cover the cost, through The Blackburn Foundation.

  Visit The Blackburn Foundation

Your monitoring coordinator can make the introduction.