Drug Testing Remains Low Among Patients on Long-Term Opioids

A more universal approach to administering and responding to urine drug testing is needed, according to a study published in Drug and Alcohol Dependence. Only one in five patients receiving long-term opioid therapy (LTOT) for chronic pain in the Veterans Affairs (VA) system undergoes urine drug testing. Further, there are racial differences in initiation of testing and discontinuation of opioids for among those that test positive for illicit drugs while taking LTOT.

Multifaceted approaches are needed to combat misuse of prescription opioids. According to the U.S. Centers for Disease Control and Prevention (CDC), more than 40 percent of all opioid overdose deaths in the United States are due to prescription opioids. While there has been increasing attention on prescribing practices, there has been less attention paid to assessing how well clinicians monitor patients for signs of misuse once opioids are initiated.

"There is a general consensus among experts in the field of pain management that urine drug testing is one of the best tools clinicians have for identifying opioid misuse, illicit drug use, and the concomitant use of sedatives or other substances that may increase the risk of overdose," write the authors led by Julie Gaither, from Yale University in New Haven, Conn.

The CDC's opioid prescribing guidelines call for clinicians test for illicit drug use in all patients with chronic pain receiving LTOT, including a urine drug testing before initiating opioid therapy and at least annual urine drug testing after that. For those with a positive test for illicit drug use or other behavior suggestive of addiction, more frequent monitoring is appropriate, experts say.

The present study examined drug testing patterns and how clinicians respond to evidence of illicit drug use among 15,366 patients (48.1 percent black and 51.9 percent white; 97.5 percent male) initiating LTOT through the VA between 2000 and 2010. The researchers used electronic health records to examine administrative, clinical, laboratory, and pharmacy data for participants of the Veterans Aging Cohort Study. Patients with a palliative or end-of-life care code were excluded. This analysis looked at the first urine drug test received by patients during the initial 6 months of LTOT. LTOT was defined as receipt of at least a three-month supply of opioids prescribed for chronic pain.

The researchers found that only 21 percent of patients received a urine drug test within the first 6 months of treatment. Black patients were significantly more likely to receive a urine drug test overall (25.5 percent versus 15.8 percent for whites). They were also significantly more likely to be tested within 1 month, 3 months, and 6 months of initiating opioid therapy, compared to whites.

"Our findings are in keeping with previous studies showing that clinicians have been slow to integrate urine drug testing into patient care, even for patients at high risk for opioid misuse and abuse," writes Gaither and colleagues. "Why some clinicians have failed to adopt this universal approach to urine drug testing and how patients are selected for testing remains unclear."

The vast majority of patients who tested positive for cannabis or cocaine (90 percent) refilled an opioid prescription within the next 60 days. Overall, LTOT was discontinued in 11.4 percent of patients who tested positive for cannabis and in 13.1 percent of those who tested positive for cocaine. However, blacks were twice as likely to have opioids discontinued after testing positive for cannabis and three times more likely after testing positive for cocaine.

"The magnitude of the discrepancy we found in discontinuation rates for blacks compared to whites suggests that in the absence of clearer urine drug testing guidelines, extraneous factors unrelated to the risks and benefits of LTOT— including racial stereotypes— may enter into the decision-making," write the authors. "In light of this potential, we believe that the safest and most judicious way forward is for clinicians to adhere to the latest guidelines from the CDC.

The authors add that clinicians need clearer guidance for how to respond to aberrant toxicology results.

Takeaway: Adherence to CDC guidelines calling for regular illicit drug testing among patients taking LTOT for chronic pain is low. Further, racial disparities exist in testing initiation and response to positive test results.