In 2014, an estimated 4.7 million Americans were dependent on opioids, including both prescription opioids and heroin (
1). Prescription opioid overdose, abuse, and misuse cost an estimated $78.5 billion in 2013 (
2). Opioid use disorder is associated with a range of health issues, including cardiovascular disease, diabetes, HIV/AIDS, and hepatitis C (
3–
10). Of particular concern is the dramatic rise in opioid overdose deaths related to prescription opioids and heroin (
11,
12). The rate of opioid-related overdose deaths has increased more than 200% since 2000. In 2015, opioids were involved in 33,091 overdose deaths (
13).
Increasing access to medications for treating opioid use disorder is widely acknowledged to be a key strategy for addressing the opioid epidemic (
11,
14,
15). The effectiveness of methadone maintenance therapy has been demonstrated in many trials (
16). Buprenorphine, a partial opioid agonist, and naltrexone, an opioid antagonist, the main focus of this article, can be readily prescribed in outpatient treatment settings and have also demonstrated efficacy (
17–
21). Poor compliance associated with oral naltrexone suggests that it may be more effective for patients who are highly motivated or patients who are closely monitored. Patients must also be free from opioids for seven to 10 days prior to initiating treatment with naltrexone.
Buprenorphine is a schedule II narcotic and can be prescribed only by a physician holding a Drug Addiction Treatment Act of 2000 waiver. Physicians are limited to prescribing buprenorphine to a maximum of 30 patients at one time in the first year of holding a wavier, a maximum of 100 patients in the second year, and a maximum of 275 patients in the third year. There are no such prescribing regulations on naltrexone.
Use of medications for treating opioid use disorder is associated with reductions in opioid use, withdrawal and craving, infectious disease transmission, and treatment dropout (
18,
19,
22–
25). Research also has shown that buprenorphine and both formulations of naltrexone are cost-effective and that their use is associated with reductions in other types of health care utilization (
26–
28). For many Americans with opioid use disorder, these medications, used in conjunction with psychosocial therapy, are the most effective treatment option (
17–
20).
Despite the efficacy of buprenorphine and naltrexone, few treatment programs in the United States prescribe them (
29). Data indicate that less than half of nonopioid treatment programs (non-OTPs; specifically, specialty treatment programs that are not licensed to dispense methadone) prescribe a single medication and that less than 40% have a physician on staff. Buprenorphine is the most commonly prescribed medication in non-OTPs, followed by oral naltrexone and injectable naltrexone (
29).
The reasons for low rates of adoption of these medications in treatment programs are complex. Financial barriers have been a long-standing challenge for patients and treatment programs. Because many patients are unable to afford these medications, treatment programs that serve clients who are predominantly low-income and uninsured are less likely to offer them. Prior research has demonstrated that treatment programs that are large, for-profit, and accredited and that also serve a higher percentage of patients with private health insurance are significantly more likely to offer treatment medications for opioid use disorder such as buprenorphine and naltrexone (
30–
37).
Additionally, access to prescribers of medications has been a challenge for many treatment programs because of a lack of resources and federal restrictions limiting the number of physicians who can prescribe buprenorphine and the number of patients they can serve. As a result, it has been difficult for specialty treatment programs to attract and retain physicians who have the capacity to prescribe medications for treating opioid use disorder. Hospital-based programs and programs with a physician on staff have historically been more likely to adopt medications (
29,
31,
36,
38).
The Role of States in Medication Adoption
Substance use disorder treatment in the United States is delivered by the more than 14,000 programs that compose the specialty substance use disorder treatment system. Approximately two-thirds of specialty treatment programs rely on Substance Abuse Prevention and Treatment block grant funding provided by the Substance Abuse and Mental Health Services Administration (SAMHSA) and administered through each state’s single-state agency (SSA) (
39–
42). SSAs are state governmental organizations responsible for overseeing and licensing substance use disorder treatment programs. Each state’s SSA organizes and administers the distribution of the block grant, including determining treatment provider qualifications, payment methods and rates, and reporting requirements (
39,
43,
44).
State policies influence adoption of medications by treatment programs (
43,
45). Rieckmann and colleagues (
45) reported that a majority of SSAs used contract language (that is, contracts with treatment programs that either required or encouraged evidence-based practices) as a tool to promote implementation of evidence-based practices, including use of medications. Other studies examining the influence of state policy on medication adoption have focused exclusively on the adoption of buprenorphine. Using data from 2006, Ducharme and Abraham (
31) found a positive association between state Medicaid coverage of buprenorphine and programs’ adoption of buprenorphine. A more recent study by Andrews and colleagues (
30) examined the adoption of buprenorphine in a national sample of OTPs and found that the odds of offering buprenorphine were greater in OTPs located in states that provided subsidies to support buprenorphine adoption.
Taken together, these studies suggest that state-targeted funding, that is, funding specifically allocated to support medications, and incentives may have a significant influence on programs’ decisions to offer medications. However, these studies report on data collected nearly a decade ago—a particularly problematic lag in light of significant changes in structure and financing of the specialty treatment system spurred by the Affordable Care Act (
30,
31). Moreover, these studies do not include oral and injectable naltrexone, important medications for treatment of opioid use disorder (
30,
31). To address this gap in the literature, this study examined the influence of state-targeted funding and technical assistance on the adoption of three medications used to treat opioid use disorder: oral naltrexone, injectable naltrexone, and buprenorphine. The study focused on non-OTPs, which represent 90% of the substance use disorder treatment system and historically have low rates of medication adoption.
Methods
This study draws data from the sixth wave of the National Drug Abuse Treatment System Survey, a nationally representative, longitudinal study of treatment programs in the United States. The National Drug Abuse Treatment System Survey uses a split-panel design with replacement sampling to replace programs that exit the sample over time and refresh the sample to ensure a nationally representative sample at each wave of data collection. Survey weights account for possible nonresponse bias and ensure that the sample was representative of the study population. Data from program directors and clinical services supervisors of treatment programs were collected from November 2013 to June 2014. Interviews were 90 minutes long and were conducted via Internet-based survey. Interviews were completed with 695 treatment programs (response rate=85.5%); see D’Aunno and colleagues (
46) for a complete description of the study methods. Of these programs, this study reports data from 456 non-OTP programs. To measure state-targeted funding and incentives for treatment medications, we conducted a 15-minute, Internet-based survey with representatives from SSAs, which included a population of all states and the District of Columbia (response rate=98%). These data were collected from October 2013 to July 2014. The institutional review boards at Miriam Hospital (Providence, RI), the University of Chicago, the University of South Carolina, and the University of Georgia approved this study.
Measures
Dependent variables.
The study included three dependent variables measuring whether treatment programs provided each of the following medications for the treatment of opioid use disorder: oral naltrexone, injectable naltrexone, and buprenorphine.
Independent variables.
Our primary independent variables of interest were designed to gauge the extent to which SSAs provided targeted funding and technical assistance to encourage the availability of medications. We assessed whether states specifically allocated block grant funding for each of the three medications and whether any state funds, other than those available through Medicaid, were used to subsidize the availability of buprenorphine. The study also measured the extent of technical assistance provided by states to treatment programs to address potential barriers to adoption of medications by using seven items: creating information technology and electronic health records infrastructure, obtaining Medicaid certification, becoming in-network providers within private insurance plans, collaborating with federally qualified health centers, collaborating with other medical providers, collaborating with mental health providers, and providing education and training to increase the number of counselors for substance abuse and dependence. [A brief description of items measuring technical assistance provided by SSAs to substance use disorder treatment providers is available as an online supplement to this article.] The response to each item was coded 1 if the state responded affirmatively and 0 otherwise. Items were then summed to create a scale ranging from 0 to 7, with higher scores indicating receipt of more comprehensive technical assistance. In addition, we conducted a factor analysis and retained the first factor. The results did not change; thus, we used the summed score for ease of interpretation.
Control variables.
We included measures of treatment programs that have been significantly related to medication adoption in prior research (
29–
37,
47–
58). These included program ownership (private for-profit, private nonprofit, and public), program type (outpatient, inpatient-residential), accreditation by the Joint Commission or Commission on Accreditation of Rehabilitation Facilities, the number of clients served by each program in the past year (log transformed to adjust for skewness), the percentage of staff with a master’s degree, and the percentage of program revenues in the past year from private insurance. We also measured each program’s percentage of black, Hispanic, and female clients in the past year.
To control for patient demand for treatment services and perceptions of market competition that might also influence adoption of medications, we measured the percentage of treatment program clients experiencing heroin and prescription opioid disorder in the past year. These measures also indicate the extent to which treatment programs specialize in these patient populations. To capture perceptions of competition, we included a survey measure that assessed whether the program director perceived an increase in competition in the local labor market in the past year.
Analytic Technique
Descriptive statistics were calculated for all study variables. Using logistic regression, we examined the relationship of state-targeted funding and technical assistance to adoption of opioid use disorder medications among treatment programs. Models accounted for the nesting of treatment programs in states. To account for sampling strata, models included sample weights using the svy command suite in Stata (
59). Imputation was conducted with the mi impute command suite in Stata (
59), to account for missing data on treatment program–level independent variables. The total number of treatment programs included in multivariate analyses varied on the basis of the amount of missing data on each dependent variable. All analyses were conducted in Stata, version 14.1 (
59).
Results
Descriptive Statistics
Among the 50 SSAs, six allocated block grant funding to treatment programs for provision of oral naltrexone, seven allocated block grant funding for injectable naltrexone, and eight allocated block grant funding for buprenorphine in 2014 (
Table 1). Fifteen SSAs reported subsidizing the use of buprenorphine with state funds other than Medicaid. Most SSAs reported providing at least some technical assistance to assist treatment programs with adoption of opioid use disorder treatment medications; on average, SSAs offered about five assistance services to treatment providers. Among treatment programs, approximately 11% offered oral naltrexone and injectable naltrexone, and 26% offered buprenorphine in 2014.
Logistic Regression Models
The adjusted odds of adopting oral naltrexone were greater in treatment programs located in states that provided block grant funding specifically for opioid use disorder medications (adjusted odds ratio [AOR]=3.14;
Table 2). The adjusted odds of adopting buprenorphine (AOR=2.47) were positively associated with provision of state funding for buprenorphine as well as the extent of state-based technical assistance provided to treatment programs (AOR=1.18). Although the odds ratios of receiving technical assistance in the naltrexone models were similar to the odds in the buprenorphine model, they were not statistically significant.
Organizational factors were also positively associated with adoption of opioid use disorder medications. The adjusted odds of adopting oral naltrexone and buprenorphine were greater in private nonprofit programs (AOR=3.59) compared with private for-profit programs (AOR=2.56). The adjusted odds of adopting buprenorphine were greater in larger programs (AOR=1.53). The adjusted odds of adopting oral naltrexone (AOR=3.14) and injectable naltrexone (AOR=2.22) were higher in inpatient and residential programs than in outpatient programs.
Market factors were also associated with the adoption of oral and injectable naltrexone. The adjusted odds of adopting injectable naltrexone were greater in programs that reported an increase in competition in the past year (AOR=2.33), and the adjusted odds of adopting injectable naltrexone were greater in programs with a higher percentage of patients with heroin use disorder (AOR=1.02).
Discussion
This national survey found that state-targeted funding was linked to adoption of two medications for opioid use disorder: oral naltrexone and buprenorphine. However, adoption of medications among substance use disorder treatment programs remains low, with less than 27% of treatment programs offering buprenorphine and less than 12% of programs offering either oral or injectable naltrexone.
Given the increase in demand for opioid use disorder treatment and the rise in opioid overdose deaths over the past 15 years, it is critically important to increase access to these medications (
11). Our findings suggest that state-targeted funding for medications may be one viable policy lever to increase their availability in treatment programs. Through the 21st Century Cures Act, states are receiving additional funding administered through SAMHSA to directly address the opioid crisis. One goal of this funding is to expand access to opioid use disorder medications. Thus, it will be particularly important to monitor how states are using these funds and whether these additional funds result in increased access to opioid use disorder medications.
Although states act relatively autonomously to make decisions about the allocation of Substance Abuse Prevention and Treatment block grant dollars to prevention, treatment, outreach, and administrative costs, SAMHSA might consider offering additional incentives to states to increase availability of opioid use disorder medications. The federal government could also encourage the Centers for Medicare and Medicaid Services to offer incentives to providers to encourage comprehensive coverage of opioid use disorder medications. This approach may be particularly important for states hardest hit by the opioid crisis. At present, only three states with the highest rates of opioid overdose deaths or opioid use disorder rates allocate any block grant funding for opioid use disorder medications (
60).
In addition to allocating a portion of treatment dollars from the federal block grant to medications, our findings suggest that subsidizing the use of medications using other streams of state funding may also be a viable strategy. Both this study and prior research demonstrate the utility of this strategy to facilitate adoption of buprenorphine (
30). However, the states using this strategy are not always the states with the greatest need. Among the 15 states subsidizing buprenorphine with state funding (other than Medicaid and the block grant), only seven states are among those with the highest rates of opioid overdose deaths, and only four states are among those with the highest rates of opioid use disorder (
60,
61).
We also found that programs located in states with SSAs that provide a greater level of technical assistance were more likely to adopt buprenorphine. This finding suggests that the availability of technical assistance indicates a more supportive state policy environment that places an emphasis on the use of evidence-based practices, collaboration with primary care and mental health providers, adoption of electronic health records, and obtaining Medicaid certification, all of which might contribute to increased accessibility and quality of treatment. Indeed, treatment providers who begin collaborating with primary care and mental health providers may gain access to prescribing staff for the first time. Taken together, these findings suggest that when states help programs overcome financial and technological barriers to offering these medications, treatment programs respond as hoped—by adopting medications.
Although SSA policy influenced adoption of oral naltrexone and buprenorphine, it did not affect adoption of injectable naltrexone. This outcome may be related to the cost of injectable naltrexone, which can be as much as $1,000 per injection. Even when the medication is covered by insurance, it still may not be an affordable option for patients. The administration of the injection also requires a higher degree of technical expertise than the other, orally administered medications (
62). Staff may need additional training, or new staff may need to be hired. Our findings suggest that the adoption and implementation of injectable naltrexone may require a greater commitment of resources on the part of SSAs and treatment programs.
In contrast to some prior research, we found that private nonprofit treatment programs were more likely to offer oral naltrexone and buprenorphine compared with private for-profit programs. There may be several explanations for this finding. First, data from the National Survey of Substance Abuse Treatment Services and prior studies that used data from this survey indicate that private for-profit programs were more likely to be early adopters of buprenorphine compared with private nonprofit programs (
31,
33). However, by 2015, the percentage of private nonprofit, private for-profit, and publicly owned programs offering buprenorphine was very similar (
63). Second, studies that found that private for-profit programs were more likely to adopt oral naltrexone compared with private nonprofit programs (
34) restricted their sample to privately funded programs. Our study did not use eligibility criteria based on sources of funding; thus, direct comparisons with these studies cannot be drawn. Third, other studies that included both samples of privately and publicly funded programs (
36) used separate variables to measure funding and profit status. Therefore, our results are not directly comparable with these prior studies. Fourth, most of these studies did not control for state policy or market characteristics, which may account for these differences.
This study had several limitations. First, the data are cross-sectional; hence, we are unable to draw any causal inferences. Second, the study did not examine the relationship between Medicaid coverage and adoption of medications because of a lack of variation in coverage. In 2014, all state Medicaid plans covered buprenorphine, and 48 states covered injectable naltrexone. Third, the survey did not ask whether states used non-Medicaid state funds to support oral or injectable naltrexone. Fourth, our study relied on self-report data, which are subject to response bias. Fifth, there may be other factors not included in these analyses that account for variation in availability of medications.
Conclusions
Given historically low rates of medication adoption in treatment programs and the rise in opioid overdose deaths and treatment admissions for opioid use disorder, increasing access to these potentially life-saving medications is imperative. SSA-targeted funding and technical assistance may be viable policy levers to increase access to effective medications in the great majority of treatment programs that do not offer medications. SSAs in many states with the highest rates of opioid use disorder and opioid-related overdose deaths are not currently using these funding and assistance strategies; thus, additional federal incentives may be necessary.