BONITA SPRINGS, FLA. – Urine drug screening is a vital part of clinical care, but many clinicians say they do not know enough about how the tests work, an expert said at the annual meeting of the American Academy of Addiction Psychiatry.
Dr. Rebecca Payne
Rebecca Ann Payne, MD, said clinicians, including residents, tend to cite little training as a reason for their uncertainty about how to interpret urine drug screen results. Also, primary care clinicians say they need more education on implementing and interpreting the screens.
The good news is that medicine and pediatric residents said they felt that a 30-minute educational program significantly boosted their knowledge base and comfort in interpreting urine drug screens, said Dr. Payne, assistant professor of neuropsychiatry and behavioral science at Palmetto Health–University of South Carolina Medical Group. She offered several points that addiction psychiatrists should be aware of:
“A positive test doesn’t necessarily mean there’s a substance use disorder,” she said. “You still need to walk through those criteria with your patients. And a positive test doesn’t mean they’re physically dependent upon it.” She said she sometimes hears from patients who say that they’d been on a certain treatment – then failed a test given by their clinician – and had their treatment stripped away.
“Drug testing is meant to be a source of information and should not dictate treatment,” she said. “I have found it’s not unusual to hear from the community that decisions are being made solely on the results of these tests, which can be problematic.”
- Point-of-care tests, which sometimes can be bought in drug stores, she said, are “much less than perfect.”
The false-positive rate for benzodiazepines has been found to be 61%; and for methadone, it is 46%; for opioids, 22%; and for amphetamines, 21%.
- Know what your lab is actually testing for, because “it’s not universal.”
She emphasized knowing the particulars of opiate testing.
“A lot of times in a hospital setting, your lab is really only testing those opiates that are directly derived from the poppy – we’re talking about things like codeine, heroin, morphine. They’re not testing for things like your semi-synthetics or your full-synthetic opiates.”
- Know the answer to the question: “Can you get a positive result on a marijuana drug screen just from passive inhalation?”
Physicians often will be confronted by patients who insist they were only in the car or in the same room with someone who was smoking marijuana. How likely is it that their test could be positive?
“Possible,” she said, “but not probable.”
Dr. Payne’s key interest areas include teaching medical students and residents, treating substance use and psychiatric disorders that are comorbid, and conducting research in addiction psychiatry.