Buprenorphine-naloxone administered daily was more cost-effective than monthly injections with extended-release naltrexone for prevention of opioid relapse, a new study found.
Researchers performed a cost-effectiveness analysis alongside a previous randomized clinical trial that compared a 24-week intervention with buprenorphine-naloxone or extended-release naltrexone plus 12 weeks of observation. The trial was conducted in adults with opioid use disorder in eight inpatient or residential treatment programs, and the primary outcome was opioid relapse-free survival. For the cost-effectiveness analysis, incremental costs combined with incremental quality-adjusted life-years (QALYs) and incremental time abstaining from opioids were the outcome measures. The analysis, which was funded by the National Institute on Drug Abuse, was published by Annals of Internal Medicine on Dec. 18.
The randomized clinical trial involved 570 patients with an average age of 34 years. Most were male and white and had public insurance (70%, 74%, and 64%, respectively). In the base-case analysis, when the health care sector perspective and a willingness-to-pay threshold of $100,000 per QALY were used, buprenorphine-naloxone was more likely to be preferable to extended-release naltrexone at 24 and 36 weeks. Similar results were noted when the societal perspective was used and with an outcome of incremental time abstaining from opioids. The researchers found that these results were sensitive to treatment costs and to the success of initiation of randomized treatment. Over 24 weeks, extended-release naltrexone cost an average of $5,317 more than buprenorphine-naloxone, primarily because the former was more expensive and required a longer detoxification period.
Limitations of the analysis included relatively short follow-up, a substantial amount of missing data, and the lack of information on patients' out-of-pocket costs and costs for social services. However, the authors concluded that based on their findings, buprenorphine-naloxone should usually be preferred over extended-release naltrexone for first-line treatment in cases where both options are clinically appropriate and patients must undergo detoxification to initiate the latter therapy. The authors noted that the certainty of their conclusions was affected by varying societal and treatment costs and that additional research identifying patients who would do better with extended-release naltrexone would help determine how their findings could affect policy decisions.
An accompanying editorial said that the health care delivery system is responsible for barriers to high-quality care in patients with opioid use disorder. Regulations currently restrict prescribing of two of the three FDA-approved drugs for this condition, and some institutions and programs prefer extended-release naltrexone “primarily because it is not an opioid,” despite documented difficulties with its use, the editorialists said. “By offering only naltrexone—a medication that most persons either will not receive or not continue—because of clinician or institutional beliefs, patients receive inferior treatment,” the editorialists wrote. “In the context of a high mortality rate and already limited access to addiction care, we need to offer the best treatment that patients will, in fact, receive and continue.”
A research letter also published by Annals of Internal Medicine on Dec. 18 looked at risk factors for chronic opioid use in opioid-naive patients newly diagnosed with neck, shoulder, knee or low back pain. The authors used the IBM MarketScan database to examine data on 412,021 patients ages 18 to 64 years whose musculoskeletal pain was severe enough to warrant a second outpatient or ED visit within 30 days of their first diagnosis. Chronic opioid use was defined as having filled 10 or more prescriptions or having at least 120 days' supply of hydrocodone, hydromorphone, methadone, morphine, oxymorphone, or oxycodone between 91 and 365 days after the initial diagnosis.
The study sample included 51% men; average age was 45 years. Annual unadjusted risks for chronic opioid use over the study period were 1.5% for multiple sites of pain, 1.4% for low back pain, 0.43% for neck pain, and 0.3% each for shoulder and knee pain. The overall risk for chronic use for the entire sample was 0.31%. Pain location and opioid use within 90 days of diagnosis were the most notable risk factors for chronic opioid use. The researchers noted that their study involved only privately insured patients and that some patients may have used opioids before, among other limitations, but concluded that while risk of chronic opioid use for musculoskeletal pain has decreased, measures could be taken to reduce it further. Patients with the risk factors noted in their study “should be followed closely and may benefit from involvement of a nonpharmacologic provider, such as a physical therapist or chiropractor,” they wrote.