Wednesday, August 3, 2011

Study Distorts Teen Misuse of Rx Pain Meds

In The News A newly reported study claims that more than 1 in 5 teenagers medically misuse controlled medications — eg, pain, stimulant, sleeping, or anxiety drugs — for which they have legitimate prescriptions, and they also may be more likely to divert those medications and to abuse other substances. However, while news headlines decried a growing epidemic of drug problems among youth, an overly broad definition of “misuse” may be distorting the data and creating confusion about the prevalence and motivations behind these behaviors in teens.

According to background information in the study article, appearing in the August issue of Archives of Pediatrics and Adolescent Medicine, U.S. children and teens have increasingly received prescriptions for controlled medications [McCabe et al. 2011]. Consequently, there have been concerns about a concomitant rise in medical misuse, abuse, and diversion of these medications. The authors define “medical misuse” as “the use of a controlled psychotherapeutic medication by a patient in a manner not intended by the prescribing health care professional, including (but not limited to) not following the prescribed dosage, using intentionally to get high, not taking the medication within a prescribed interval, or co-ingesting with alcohol or other drugs.”

For this study, Sean Esteban McCabe, PhD, from the University of Michigan, Ann Arbor, and colleagues conducted a Web-based survey from December 2009 to April 2010. The 2,597 respondents who completed the survey were students at middle schools and high schools in two southeastern Michigan school districts; mean age was about 15 years, 65% were white, and 51% were female. The survey included standard measures of substance use, including questions about medical use, misuse, and diversion (selling, giving away, or trading) of controlled medications; cigarette smoking in the past month; binge drinking in the past two weeks; nonmedical use of prescription medication; and marijuana and other illicit drug use in the past year.

Of the 18% (468/2,597) of respondents who said that during the past year they had used, for medical purposes, one of the four controlled medication classes mentioned — pain, stimulant, sleep, antianxiety — 22% (103/468) also said they had “medically misused” these medications (representing about 4% of the total sample population), with the vast majority of them misusing by taking too much. Females were significantly more likely to be medication misusers than males.

Subjects defined as frequent users of controlled medications (at least 10 instances) were more likely than less-frequent users to engage in misuse. Adolescents who misused their controlled medications were also more likely to use alcohol and other drugs, and to divert these medications to others.

The authors conclude that, “Clinicians must balance the risks and benefits of controlled medication use with the abuse potential when assessing, treating, and monitoring their patients.” And, healthcare providers should “consider prescribing controlled medications with less potential for substance abuse and diversion.”

COMMENTARY: There are numerous limitations of this study’s methodology and data reporting that raise questions about the utility and external validity of results:

  • Perhaps most important, the definition of “medical misuse” in this study does not distinguish between medication non-adherence for medical purposes — eg, taking more of a drug or more often than prescribed for symptomatic relief — compared with recreational use to get “high,” relax, etc. While the former might relate to misprescribing of inadequate dosages in the first place, the latter behavior suggests what is more typical considered nonmedical use or substance abuse.

  • As expected, the overly broad definition of “misuse” exaggerates the overall prevalence of such undesirable behaviors; yet, it is noteworthy that only a relatively small proportion of all respondents (about 4%) indicated such misuse and 93% of those “took too much,” as calculated from data in the report — probably for medical purposes.

  • Medications prescribed for pain examined in the survey included exclusively opioid formulations, and only 14% of all respondents had received such prescriptions in the past year; 20% of them (2.8% of all respondents) indicated misuse and almost all of that (18%) involved taking more than prescribed. Of greatest concern, 9% of those prescribed opioids abused them to get “high” or to increase alcohol or other drug effects, but this cohort represented only 1.3% of the total sample of youths responding to the survey.

  • Interestingly, larger percentages of respondents prescribed stimulants, sleeping aids, and antianxiety drugs admitted abusing them for nonmedical purposes; 11%, 17%, and 16%, respectively. These medications were prescribed much less frequently among the respondents than pain relievers, but their abuse potential in this population may be greater than opioids.

  • Clearly, there is a relationship between youth misbehaviors — whether noncompliance with prescribed drug regimens or abuse of those drugs in some way — and diversion of the drugs to others. In most instances the study found that respondents “loaned” or gave the drugs in question to others, but it is unknown whether this was for medical or nonmedical (ie, abuse) purposes and the motivations behind sharing can make a big difference.

  • Finally, two further limitations of this study are worth noting: a) data were gathered via a voluntary, self-administered online survey, with all of its inherent problems of recall bias and distortions of information (the researchers did not do any cross-checking of reliability via face-to-face interviews); b) respondents, who were required to have Internet access and be self-motivated to complete the survey, represented only two school districts in a small part of the U.S. Therefore, any generalizing of the findings to a broader population of youth should be done very cautiously, and news reports do not take this into account.

The findings from this present study are not surprising or entirely new. About two years ago, this same research team headed by McCabe, and writing in the same journal, reported a similar survey [See UPDATE here]. They noted that roughly 12% of the students surveyed had used opioids for “nonmedical” reasons. However, a large percentage (45%) said that they “misused” the analgesics specifically to relieve physical pain. Furthermore, when pain relief was a primary reason for misusing opioids the students were less likely to use other addictive drugs, alcohol, or marijuana. This appears to confirm that many young persons were specifically seeking analgesic effects afforded by opioids, which might raise concerns about the medical mistreatment of pain in this population.

While problems of youth being nonadherent to prescribed drug regimens or abusing medications in some way gather a great deal of justified attention, data from these studies by McCabe and colleagues do not appear to support the notion of such behavior as an “epidemic.” While news headlines such as “One-Fifth of Teens Taking Controlled Drugs Misuse Them” in reference to the most recent study are technically accurate they also distort the true prevalence of the problem. Overly broad, and somewhat vague, definitions of “misuse” are both deceptive and unhelpful in addressing the problems, and McCabe et al. concede this measure “has not undergone formal psychometric evaluation.”

In their discussion, the authors stress a need for greater patient education to enhance compliance with prescribed drug regimens, and to caution about the harms of diversion (no matter how innocently intended). This seems both essential and reasonable. Yet, how many prescribers (or pharmacists) take ample time to properly counsel their young patients — and/or the parents — about the importance of medication compliance and safety?

REFERENCE: McCabe SE, West BT, Cranford JA, et al. Medical Misuse of Controlled Medications Among Adolescents. Arch Pediatr Adolesc Med. 2011;165(8):729-735 [abstract here].