Friday, May 21, 2010

Which Patients With Pain Are Likely Drug Abusers?

A new study proposes a series of risk factors for identifying primary-care patients with chronic pain who are most likely to abuse prescription medications and other drugs. However, there are some hazards inherent in applying such stereotypes in everyday clinical practice.

Researchers from Boston University School of Medicine enrolled 597 participants in their study at an urban academically-affiliated hospital [Liebschutz et al. 2010]. Subjects were 18 to 60 years old (mean age 46 years), 41% male, 61% black, largely unemployed and poor, and all had pain for >3 months and were taking prescription or nonprescription analgesics. More than half (58%) of participants had no lifetime history of any substance-use problem; however, roughly 18% (n=110) were assessed as having a prescription drug use disorder (PDUD) — of whom most (90%, n=99) also had an additional substance use disorder (SUD) — and 24% had an SUD other than abuse of prescription drugs.

Which patients were most likely to be drug/substance abusers? In adjusted analyses, compared with those not having any current or past drug/substance use disorder, those with PDUD were 5 times more likely to report having spent time in jail, 3.4 times more likely to have a family history of SUD, and 3.6 times more likely to smoke cigarettes. Additionally, those with PDUD were 3.8 times more likely to have greater pain-related disability, and to be white (3.2 times greater likelihood), male (90% greater odds), and/or have PTSD (90% greater odds). Except for race, the same factors also predicted having another SUD, as compared with those without any drug/substance-use problem. Insurance coverage, employment, income, education, and age were not associated with drug/substance use disorders of any type in this sample.

According to lead author Jane M. Liebschutz, MD, MPH, FACP, quoted in a news article, "These data strongly suggest that physicians treating patients with pain should assess for substance use disorder prior to prescribing opioid analgesics. This research may help direct care, including treatment for substance use disorders, as primary care physicians may not be as aware of the overlap between pain and addictions. In particular, physicians may not think of assessing for time spent in jail, which was the largest predictor of having PDUD" [Medical News Today 2010].

COMMENTS & CAVEATS: According to this research, any patient with chronic pain should be suspected of being likely to abuse prescribed medications and/or other drugs if they are a white male with severely disabling pain, spent time in jail, smokes cigarettes, has a family history of substance abuse, and/or suffers from post-traumatic stress disorder. Using commonly available assessment instruments, these factors can be readily identified and, presumably, the more factors evident in a patient the more strikes against him.

However, there are some troubling aspects of this research. First, the high 42% prevalence of prescription drug abuse and/or other substance-use disorders found in this study seems to characterize the particular and limited inner-city population examined but would doubtfully be typical of most primary care medical practices; so, its external validity must be questioned. Second, even if the factors predisposing to prescription drug abuse are valid, this sort of stereotyping (recently disparaged as “profiling”) could be misleading and, if inappropriately applied, could encourage mistreatment or undertreatment of patients with pain. In effect, this line of research — which was funded by the National Institute of Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism — raises “red flags” that may be somewhat arbitrary and it does not suggest any solutions for managing risk factors while still providing proper and adequate pharmacologic pain management.

REFERENCES:
> Liebschutz JM, Saitz R, Weiss RD, et al. Clinical Factors Associated with Prescription Drug Use Disorder in Urban Primary Care Patients with Chronic Pain. J Pain. 2010(Mar 25); online ahead of print [
abstract].
> Medical News Today. In A Primary Care Setting Researchers Define Traits Associated With Prescription Drug Disorders. 2010(May 17) [
available here].