Saturday, September 11, 2010

Opioid-Analgesic Addiction Risk Factors Reported

AddictionResearchers at a large healthcare system found that up to 1 in 4 patients prescribed long-term opioid therapy for noncancer pain may have developed addiction to the medication. However, this is probably not representative of prevalence rates throughout the U.S.

Using electronic health records from the Geisinger Health System in Pennsylvania, investigators identified outpatients receiving 4+ opioid prescriptions in the prior 12 months for back pain and related orthopedic conditions [Boscarino et al. 2010]. Diagnostic interviews were conducted with 705 of those patients to assess opioid use disorders and related risk factors. Their preliminary analyses found that current opioid dependence (addiction) might be as high as 26% [95% confidence interval (CI) = 22.0–29.9] among the patient population studied.

Data analyses indicated that addiction was significantly associated with a number of variables often in the patients’ medical records: age <65; history of opioid abuse; high dependence severity; major depression; concurrent psychotropic medication prescription. Four variables combined (age, depression, psychotropic medications, and pain impairment) predicted an 8-fold increased risk for addiction, as compared with patients not having those factors. As might be expected, the addiction risk was further increased greatly in those with a history of opioid abuse or addiction.

The authors conclude that opioid abuse and addiction among patients prescribed opioid analgesics in the United States may be higher than expected. A small number of factors, many of which are documented in the medical record, may be helpful in predicting opioid use problems in outpatients prescribed long-term therapy.

COMMENTARY: Founded in 1915, Geisinger is a physician-led health care system serving 43 counties and 2.6 million people in Pennsylvania. The key factors predisposing to opioid abuse or addiction identified in this study are not new, and the researchers indicated that those factors were typically indicated in patients’ medical records. So, it is curious that control measures had not been instituted and the prevalence of purported addiction was so high in this patient population. It cannot be assumed from this research that 22% to 30% of patients prescribed long-term opioid therapy nationwide may develop addiction.

Certainly, prudent prescribing of any opioid analgesics should take into account risk factors such as past problems with substance use (including alcohol), current psychiatric status, and concurrent medications. According to accepted guidelines, such factors may not contraindicate opioid analgesia but well-defined procedures should be instituted to more carefully monitor such patients and involve addiction-specialist consultation as appropriate. If anything, this study may signal what others have often advocated — a need for better healthcare provider education on the proper and safe prescribing of opioid analgesics, along with appropriate patient education.

[ADDENDUM: The validity of this study has been refuted in later UPDATES articles; for example, see here.]

REFERENCE: Boscarino JA, Rukstalis M, Hoffman SN, et al. Risk factors for drug dependence among out-patients on opioid therapy in a large US health-care system. Addiction. 2010(Aug); online ahead of print [abstract here].