State-level Influences on Buprenorphine Utilization: Variations in Opioid Addiction Treatment
Research Objective: Buprenorphine is a medication used to treat opioid addiction. Physicians are required to have special Drug Enforcement Agency certification to prescribe buprenorphine. Although it is more accessible and potentially safer than methadone, the leading opioid addiction treatment modality, there appear to be state-to-state variations in rates of buprenorphine adoption and use. The purpose of this study was to identify state-level influences on the volume of buprenorphine prescribed, using a limited set of supply and demand measures. Study Design: We developed a database using data on buprenorphine prescribing and factors hypothesized to influence variations in prescribing obtained from the Drug Enforcement Agency, the Substance Abuse and Mental Health Services Administration, the National Conference of State Legislatures, and other sources. All data were from 2005-2008. Factors included the prevalence of past-year use of heroin and/or prescription analgesics, the number of certified buprenorphine prescribers per 10,000 users, the number of opioid treatment programs (OTPs) per 100,000 users, total state spending for substance abuse treatment and prevention, and Medicaid coverage of buprenorphine. Linear regression models were constructed with the log of the cumulative grams of buprenorphine distributed in each state in 2008 per 1000 users as the dependent variable. Population Studied: 50 states and the District of Columbia. Principal Findings: The mean prevalence of past-year opioid use was approximately 5%. From 2005 to 2009, the mean amount of buprenorphine per 1000 users increased from 13g to 97g per year. In 2008, the population-adjusted amount of buprenorphine prescribed was highest in Vermont, Maine, and Massachusetts, and lowest in South Dakota, Iowa, and Kansas. The supply of certified physicians per 10,000 users was highest in Vermont, Maine, and the District of Columbia and lowest in Arkansas, Iowa, and Idaho. The number of OTPs per 100,000 users was highest in DC, Maryland, and Rhode Island, whereas 4 states had none (Wyoming, North Dakota, Montana, South Dakota). In unadjusted bivariate analyses, higher numbers of physicians and of OTPs were significantly associated with higher buprenorphine volume. In multivariate analyses, only the supply of physicians remained significantly associated. Conclusions: Buprenorphine use has increased rapidly over the past 5 years. After accounting for variations in state-level epidemiology of opioid use, buprenorphine volume in 2008 was highest in Vermont, Maine, and Massachusetts. Physician supply was significantly associated with greater buprenorphine use, whereas the level of state spending on substance abuse treatment and Medicaid coverage did not appear to predict buprenorphine volume. Implications for Policy, Delivery or Practice: Buprenorphine utilization is closely tied to the supply of certified buprenorphine prescribers. Reasons for the wide variation in prescriber supply across states are unclear and require further study. State policies, as reflected in per capita spending or Medicaid coverage, do not appear to affect buprenorphine utilization directly, but may do so indirectly by influencing the supply of certified physicians. States wishing to increase access to buprenorphine may be able to do so by encouraging more physicians to seek certification and by facilitating training to achieve certification. Changes in federal drug control policy, which limits the number of buprenorphine patients per prescriber, could also increase access.
Lisa M. Lines MPH and Robin E. Clark PhD. "State-level Influences on Buprenorphine Utilization: Variations in Opioid Addiction Treatment" AcademyHealth. Seattle, WA. Jun. 2011.
Available at: http://works.bepress.com/lisa_lines/2