Reports call for closer attention to drug testing accuracy

A research leader with San Diego-based Millennium Health believes many addiction treatment organizations would benefit from shedding outdated attitudes about drug testing, from lack of a broad view about potential test inaccuracies to a “gotcha” mentality about how test results should be used with respect to a program's patients.

Steven D. Passik, PhD, Millennium's vice president of clinical research and advocacy, is a co-author of two articles published in the January-February 2015 issue of the Journal of Opioid Management, with one describing results of research on the limits of traditional on-site immunoassay testing and the other an editorial describing how drug testing can further the goals of states' prescription drug monitoring programs (PDMPs). The articles were supported by Millennium Health and drug testing unit Millennium Laboratories. Passik indicated in an interview with Addiction Professional last month that proper testing guidelines could move the field toward processes that would improve testing's effectiveness while not breaking the bank for treatment facilities.

“When urine drug testing first came into addiction medicine, the field borrowed a method and mindset from vocational testing,” says Passik. “Immunoassay was cheap, and there were some inaccuracies.”

Study data

The published study, using 2012 and 2013 addiction treatment client data from Millennium Health and Millennium Laboratories databases, makes the case for programs' wider use of confirmatory liquid chromotography mass spectrometry testing. Just under 4,300 tests that underwent confirmatory analysis were included in the study.

A total of 48.5% of the analyzed urine specimens were classified as being in full agreement with reported medications. However, 25.6% detected an unreported prescription medication, and 9.3% included both an unreported prescription drug and an illicit drug. The most commonly detected prescription medications with no evidence of an actual prescription were amphetamines, followed by the pain medication tramadol.

Exploring the results of prior immunoassay testing, the researchers found that Ecstasy and amphetamines were the drugs most often missed in these tests. Conversely, PCP and Ecstasy were the drugs with the highest percentage of positives generated when no drug was actually present.

Passik says treatment programs often have not grasped the implications of potentially common errors in their on-site testing. No one would accept similar percentages of errors in an area of healthcare such as detecting tumors, he says.

“There is little doubt that there are problems with false positive results on [immunoassay], particularly with implications for court-mandated patients,” the journal article states. “However, the high number of missed cases of ongoing drug use or relapse in patients in treatment when [immunoassay] is the only form of testing utilized is notable.”

The article added, “The missed opportunity for the detection of relapse earlier in a patient's course is an area in which more accurate testing may have a huge impact on patient outcomes.”

Passik adds, “You find that the old ways of thinking die hard sometimes. Some programs still have a hard time getting past the 'gotcha' element of testing,” as opposed to using testing as a treatment tool.

He says a move toward more standardization of testing protocols, as promoted by organizations such as the American Society of Addiction Medicine (ASAM), could allow for more reliable but still affordable results. No more than three immunoassay tests and one confirmatory test per week for each patient would suffice for treatment programs, he says.

Monitoring programs

The journal editorial discusses the proliferation of PDMPs, which now exist in every state except Missouri (which reportedly is working to establish one). Passik says that while the effects of these initiatives to combat opioid misuse remain unclear, many have misconceptions about their reach. At one recent meeting he attended, a participant asked why drug testing was needed at all in a state with a strong PDMP—ignoring the numerous ways outside of medical settings in which someone might obtain and then misuse prescription medication.

The editorial states that drug testing and a PDMP should be used in a complementary fashion as an objective patient measure. It found in an examination of past data from states with and without an active PDMP that both groups of states still had wide variations in the percentage of drug tests in full agreement with reported medications.

One area that Passik would like to see changed is the requirement in many states that a prescriber check the system on the occasion of every patient visit for patients receiving opioids. It would make more sense, he says, to establish algorithms that base these checks on individual patient circumstances, rather than to create the administrative burden associated with requiring a check every time for every patient. He adds that PDMPs in adjoining states need to be able to communicate with each other in order to uncover more border-crossing activity to obtain medication.