The number of Medicaid enrollees receiving medication treatment with methadone and buprenorphine rose from 2002 to 2009 because of the availability of buprenorphine. A cause for concern, however, is that medication treatment increased at a much higher rate in counties with lower poverty rates – and lower concentrations of black and Hispanic residents.
“Concerted efforts are needed to ensure that [medication treatment] benefits are equitably distributed across society and reach disadvantaged individuals who may be at higher risk of experiencing opioid use disorders,” wrote Bradley D. Stein, MD, PhD, and his colleagues. The report was published in Substance Abuse.
Dr. Stein, of Rand Corporation, and his colleagues set out to assess the changes in medication treatment use over time and how medication treatment was being used at the county level – in addition to the associations between poverty, race/ethnicity, and urbanicity. The research team analyzed Medicaid claims from 2002 to 2009 from 14 states, representing 53% of the U.S. population and 47% of 2009 Medicaid enrollees. The states selected in the analysis, chosen to represent regional and population diversity, were California, Connecticut, Florida, Georgia, Illinois, Louisiana, Massachusetts, Maryland, New York, Pennsylvania, Rhode Island, Texas, Vermont, and Wisconsin. The researchers looked at medication treatment use among 18- to 64-year-old Medicaid enrollees, excluding people who were eligible for both Medicare and Medicaid.
The variables for who received medication treatment and data on county characteristics were well defined. Individuals who had received either methadone or buprenorphine were identified as receiving medication treatment. Some patients (3% or less) used both methadone or buprenorphine but were categorized as methadone users in the analysis to better elucidate the role of buprenorphine in medication treatment. Counties were classified as low poverty if the percentage of the county population was below the median (less than 13.5%) of the counties in the 14 states in the analysis and the federal poverty line.
The racial/ethnic makeup of a county was determined to be low percentage of black people if the percentage of the black population was below the median (less than 5.6%) in all counties. Similarly, a county was considered low percentage of Hispanic residents if the proportion of the Hispanic population was below the median of less than 4.2%, reported Dr. Stein, who also is affiliated with the University of Pittsburgh.
The analysis showed that from 2002 to 2009, the proportion of Medicaid users receiving methadone increased by 20% (42,235 to 50,587), accounting for a fraction of the 62% increase in Medicaid enrollment (42,263 to 68,278). The real driver in increased medication treatment rates was the adoption of buprenorphine, which soared from 75 in 2002 to 19,691 in 2009. In 2009, 29% of Medicaid enrollees received medication treatment with buprenorphine. The growth of medication treatment varied by the characteristics of a county’s population. In 2002, urban counties had substantially higher rates of primarily methadone therapy than did rural counties (P less than.001). But no significant differences were found across the county based the concentration of black residents or poverty. Communities that did not have low concentrations of Hispanic residents experienced higher rates of medication treatment, regardless of poverty (P less than .01 for low poverty and not low poverty)