Despite a rapid expansion in the use of buprenorphine-naloxone (bup-nx) as a treatment for opioid use disorder, there is little understanding of the patterns of treatment. In a newly published-ahead-of-print Medical Care article, Brendan Saloner and colleagues from Johns Hopkins used an all-payer claims database to investigate what factors predict the duration of treatment, dosage, and continuity of treatment for bup-nx.
Bup-nx has advantages over other similar treatments, such as methadone, because it may be dispensed and prescribed in physician offices (with the stipulation that it should be used a part of a comprehensive treatment program that includes counseling or other social support). The phases of treatment are: (1) induction, (2) stabilization, and (3) maintenance. Induction requires medical monitoring, while stabilization involves altering dosing based on behaviors and symptoms. The maintenance phase can potentially be indefinite. Without knowledge of current treatment patterns, we cannot begin to estimate the effects on health and well-being or evaluate the effectiveness of different courses of action.
Saloner and colleagues started with a cohort of individuals who had filled at least 2 prescriptions for any opioid medication between 2006 and 2013 in 11 states. The main inclusion criteria for the study was having started bup-nx treatment between January 2010 and July 2012 (capturing incident use and 13 months of follow-up). The final sample included 27,273 individuals.
About 41% of individuals were treated for at least 6 months, with a mean episode length of 266 days (median=118 days). Based on the amount filled, individuals got a mean daily dosage of 14.1 mg/d). About 30% of those studied had low possession ratios and 26% had medication interruptions of at least 2 weeks.
Retention in treatment was similar for patients who got prescriptions from PCPs and psychiatrists, but lower for patients who got them from other specialists, holding all else equal. Surprisingly, given what we know about out-of-pocket payments and the use of healthcare, patients who had treatment paid for my Medicaid FFS, Medicare Part D, or third-party commercial, had lower odds of being retained at least 6 months than patients who self-paid for the majority of their treatment (and this pattern also held true for length of treatment). Despite controlling for an array of county-level factors, state of residence/filling location was significantly related to retention.
Average daily doses were higher for patients who had treatment paid for by Medicaid FFS, Medicare Part D, or third-party commercial than for self-payers (differences ranged from 0.41 mg/d to 1.37 mg/d). Individuals who got prescriptions from psychiatrists, rather than PCPs, had a slightly lower mean daily dosage (-0.77 mg/d less, 95% CI -1.17 to -0.38). The results combine to form an interesting picture of opioid treatment and directions for further study.
As pointed out by the authors, insurance plans may place time or dollar limits on coverage for opioid use treatment. Additionally, the supply of physicians who can prescribe bup-nx is limited. Also, as mentioned by the authors, little is known about how treatment patterns relate to clinical health and well-being outcomes–a clear area where more research is needed.