A nationwide study found that 3 in 5 patients may be noncompliant with prescribed drug regimens, as detected by urine drug testing. The findings further suggest a majority of persons treated for pain may be misusing medications in ways that pose health risks; from missing doses to taking unauthorized drugs. However, there are many factors that might account for these outcomes and should be considered before leaping to conclusions about patient misbehavior.
The recently released study — a Quest Diagnostics Health Trends™ Report titled, “Prescription Drug Misuse in America, Laboratory Insights into the New Drug Epidemic” — describes an analysis of roughly 76,000 urine drug tests (UDT) of patients from 10 years of age and older, in 45 states and the District of Columbia, performed during 2011. Samples came from a wide variety of practices, including pain specialty clinics and hospitals, but excluded drug rehabilitation clinics. [The full report PDF is available here.]
Patients were tested for the presence of up to 26 commonly prescribed medications, including analgesics, and illicit drugs, such as cocaine and marijuana. Qualitative, high-performance mass spectrometry assays were based on orders from healthcare providers, which specified prescribed medications as well as all other drugs, including illicit substances, that should be tested.
”Consistent” results indicated that only prescribed drugs, as indicated on the test order form, were detected. ”Inconsistent” results suggested either the patient a) did not take the prescribed drugs, b) took the prescribed drugs plus other, unauthorized drugs or substances, or c) took only unprescribed or unknown drugs/substances. Quantitative testing, assessing specific amounts of detected drugs/substances, was not reported.
Results indicated that 63% of patients tested had results that were “inconsistent” with expected findings (see graph). Of that 63%, none of the prescribed drugs indicated on the test request were present in 40% of samples. In nearly a third of inconsistent tests (32%), other drugs in addition to those prescribed were detected. And, in 28% of cases, completely different drugs than expected by test-ordering practitioners were found.
There were high rates of inconsistence across all drug classes tested, including pain medications (44%), central nervous system depressants (50%), and stimulant medications (48%). Other study findings included:
- Males and females were equally likely to have inconsistent test results; although, findings of illicit-drugs in males were greater, with 21% of males testing positive for cocaine, marijuana, or PCP, compared with 15% of females.
- All age groups demonstrated high rates of inconsistence (see graph). As many as 70% of children 10 to 17 years of age and 73% of young adults 18 to 24 years of age were inconsistent with clinician orders. Older patients were also at high risk, with inconsistent results found in 1 of 2 (50%) adults 65 years of age or older tested.
- Inconsistence rates were similar for low-income (median ≤$29,000/yr) and higher-income (median ≥$80,000/yr) groups, although patients at lowest income levels were more likely to test negative for their prescribed drugs than those with higher income (42% compared with 35% inconsistence, respectively). Note: median income was determined by an indirect measure based on 2010 U.S. Census data by ZIP code.
- Inconsistencies in test results were found in 72% of samples from Medicaid beneficiaries, compared with 60% of patients receiving Medicare and 62% among those with private health insurance plans.
Of added importance, data were available for nearly 7,000 patients who were tested for pain medications — eg, opiates, oxycodone, methadone — at least twice, 30-days or more apart. Overall, the inconsistency rate for these medications fell from 41% initially to 34% at retesting. More specifically, half of the patients who were inconsistent for pain medications on their first test became consistent on repeat testing; conversely, and offsetting this somewhat, nearly a quarter of patients with pain who were consistent at initial testing became inconsistent on retesting a month later.
The report authors — all of whom are Quest Diagnostics employees — concluded that, “Our data suggests that the majority of patients tested misused their prescribed drugs.” And, high rates of such problems occurred across all demographic factors, including age, income level, and health insurance coverage.
COMMENTARY: Prescription drug misuse is of great concern in the United States and worldwide. This may range from noncompliance with prescribed regimens to nonmedical use to illicit diversion. As this study suggests, there can be stark differences in the medications that healthcare providers may think their patients are taking and the drugs or substances determined by objective, highly sensitive urine drug testing.
This study’s findings are startling, but it must be noted that “inconsistence” does not necessarily denote “misuse” in the sense of malevolent aberrant behavior. Furthermore, retrospective data-mining studies such as this have many limitations; usually more questions are raised than are answered, even though the questions can be important and worthwhile.
Although the database for the present study was large, it is unknown if this represented a random sampling of a broad patient population or if a significant proportion of testing was ordered primarily on patients suspected of misusing medications. The report authors concede that they were unable to confirm drug misuse through access to medical records or clinical evaluations, and patient variations in metabolism, hydration state, or time of last medication dosing may have affected the reliability of some results. It is also possible that some clinicians neglected to specify on the test order form all drugs that the patient was already known to be taking.
On the other hand, there are some important strengths of this report that should be considered. It examined a broad range of medications and substances, not just opioids, that are encountered in clinical practices treating persons with pain. Also, a wide cross section of practitioners in diverse clinical settings were included. And, patients of both genders and ages from childhood through elderly years were included; many studies of this type look only at adults.
In this study population, 6 of 10 patients were found to have inconsistencies in UDT results, which is of great concern. However, two additional possibilities that might have affected outcomes should be considered:
- Before ordering UDTs, practitioners may not have been asking patients pertinent questions about all medications they were taking, including medications prescribed by other healthcare providers, and what other drugs/substances they were using.
- If asked, patients may not have been completely forthright in their answers; either innocently — eg, confusion or forgetfulness about what they were prescribed — or deceptively to cover for what they knew was improper use or diversion.
Whether or not complete and reliable information is gathered, UDT becomes an important clinical tool providing objective confirmation of a patient’s medication and drug use status. When there are inconsistencies, it should mark the beginning of further fact-finding to understand what is going on with the patient, and there are some additional points to consider…
- As might be expected, the findings of this study imply that less affluent patients may be more likely for financial reasons to limit or forgo taking their prescribed medications as directed. Some patients may be reluctant to admit that they cannot afford their medications or are taking them less frequently than prescribed to make them last longer.
- A subset of patients may not know what other healthcare providers have prescribed for them, or may have forgotten. Confusion or memory lapses should be expected in elderly persons or in those with cognitive deficiencies of any sort.
- It is alarming that youngsters in the 10 to 17 age bracket had a 70% rate of inconsistent UDT findings. Among the pre-teenagers in this bracket, it could mean that they were taking their medications improperly on their own, without adult supervision. A high rate among the teenagers is consistent with the latest research suggesting that these are prime years for drug experimentation [see study here].
- Practitioners also need to be aware of the possibility for false findings, perhaps due to individual patient variations in drug metabolism or misunderstandings about UDT interpretation (eg, parent drug being absent but metabolites being appropriately present).
- A final point of concern raised by the study is that it cannot be assumed that patients who test either “consistent” or “inconsistent” on one occasion will remain so at a followup time point. And, this might occur even among the most expectedly compliant patients; so, ongoing UDT can be meaningful.
Prescription medication or other substance misuse of any sort may incur dangerous drug combinations, compromise patient response to pain therapy, or fuel abusive or addictive drug use, among other concerns. UDT can provide vital clinical information as a component of the patient counseling and education process, with an ultimate goal of enhanced safety and better pain management outcomes.
Further research is needed, preferably well-designed prospective investigations rather than data-mining exercises, to better understand the specific factors behind “inconsistent” UDT results as found in this study. Too often, such outcomes are assumed to portray intentional and deceitful misbehaviors by patients — possibly indicative of abuse, addiction, or diversion — and UDT is viewed as a “lie detector” or “rule-enforcement” measure. This is unfortunate and imprudent. Better research could likely demonstrate that the vast majority of “inconsistent” findings are due to misinformation, misunderstandings, or easily corrected forms of medication nonadherence.
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