Friday, January 22, 2010

Long-Term Opioid Use for Back Pain – Who, Why?

Back PainResearchers from multiple centers in the United States assessed predictors of opioid analgesic use among patients with back pain due to lumbar disc herniation or spinal stenosis. Smoking and nonsurgical treatments were the most significant reasons for continued opioid use; although, fewer than 1 in 10 patients used opioids for 2 years and the importance of smoking as a factor is debatable.

Data for this present study reported in the Journal of Pain were derived from 2,110 patients recruited from 13 spine specialty centers in 11 states as part of a larger study, called “SPORT” (Spine Patient Outcomes Research Trial) [Krebs et al. 2010]. At the outset, roughly 4 of 10 patients (42%) reported taking opioid analgesics and most (78%) said they took opioids daily. Of these patients, 25% reported continued use at 1 year and 21% were still taking opioids at 2 years (only about 9% of all patients in the study). Who were these persons taking opioids?

The researchers examined demographic factors, medical history, and lifestyle information for each subject. At baseline, compared with patients who were not taking opioids, the opioid-analgesic-using patients were more numerous in the lumbar disc herniation group, younger, less educated, less likely to be employed, more likely to have applied for disability, more likely to report a history of mental disorders, and more likely to smoke tobacco. At both the 1-year and 2-year followup points, smoking and the use of nonsurgical treatments were the only significant factors that predicted the continued use of opioid analgesics. Among patients who reported no opioid use at the beginning of the study, 8% reported starting opioid therapy at 12 months and 7% at 24 months; however, there were no significant predictive factors in these patients. Data on specific opioid analgesics taken, and their dosages, were not collected.

COMMENTARY: It should be noted that available nonsurgical treatment options included physical therapy, education/counseling with home exercise instructions, and NSAID agents if appropriate. For patients who did not respond, there were additional physical, psychological, and pharmacologic therapies (including opioids) available based on individual patient needs. Non-surgical treatments were helpful to many and opioid use declined nearly 5-fold from 42% to 9% of patients in the study. Yet, the tone of this report, whether intentional or not, seems to depict a negative outlook toward opioid therapy for these specific back conditions — disc herniation or spinal stenosis — which alternatively can be surgically treated. An underlying message appears to be that the risks of surgery (not discussed in the article) may be preferable to the risks of long-term opioid therapy (discussed in some detail). In this article, the researchers did not report on acceptable pain relief and related outcomes achieved by surgical compared with nonsurgical approaches, and it also would seem that the choice of surgery versus other treatments would (or should?) depend on factors other than the prospect of long-term opioid therapy. (In fairness, it should be noted that earlier reports on the SPORT study did indicate relatively favorable outcomes for surgical approaches [abstracts here and here].)

As baseline, 22% of opioid users and 14% of non-opioid users were tobacco smokers, which are statistically significantly differences but the prevalence of smoking in opioid users was comparable to national averages [data here] at the time of study data collection. The authors note that baseline cigarette smoking independently predicted continued long-term opioid analgesic use, and further state that “smoking may be a marker of substance use disorders in these populations.” However, data collection did not include formal assessments of substance-use disorders and fewer than 2% of participants indicated a history of alcoholism or drug addiction in questionnaires. Therefore, using smoking as a surrogate predictor of past or present substance use problems, which consequently influenced opioid-taking is highly questionable. In contrast to what the authors seem to have intended, this article appears to support the possibility that appropriate non-surgical therapies and the judicious use of opioid pain relievers may be useful for averting or delaying invasive surgery in select patients with painful disk herniation or spinal stenosis.

REFERENCE: Krebs EE, Lurie JD, Fanciullo G, et al. Predictors of long-term opioid use among patients with painful lumbar spine conditions. J Pain. 2010;11(1):44-52 [abstract here].