As the “epidemic” of opioid use disorder (OUD) sweeps through the United States, causing death and disability, enrollment and retention of people with OUD in opioid agonist treatment (OAT) have emerged as an important clinical objective (
1,
2). OAT retention is associated with substantial improvements in medical morbidity and social functioning as well as reduced HIV transmission and criminal behavior (
3–
6) and mortality (
7), such that OAT with either buprenorphine or methadone has become the standard medical treatment for OUD (
4,
8). Although only a small proportion of eligible patients with OUD are engaged in either OAT or other treatments (
9), OAT utilization has steadily increased over the past decade, mainly driven by the increased accessibility to buprenorphine that can be provided in less restrictive office-based practice, unlike methadone maintenance (
6,
10–
15). On the other hand, it has been suggested that long-term retention may be lower in buprenorphine treatment compared with methadone treatment (
16,
17), which poses a significant clinical challenge because treatment retention is crucial for therapeutic success (
7,
18).
There are limited data on long-term retention in buprenorphine treatment for OUD beyond six and 12 months (
17,
19), and the influence of diverse sociodemographic, clinical, and service use characteristics on OAT retention has been examined in few large studies (
20). A recent national study based on data from the Veterans Health Administration (VHA), an integrated health system caring for U.S. veterans at little or no copayment expense, showed 61% retention a year after buprenorphine initiation among mostly male veterans with OUD and high rates of general medical and psychiatric comorbidity (
21). Among numerous sociodemographic and diagnostic characteristics that were evaluated, only black race had a discernible (and negative) independent association with buprenorphine treatment retention.
In this observational study, we used claims data from the MarketScan Commercial Claims and Encounters Database (IBM Watson Health) documenting sociodemographic and clinical characteristics, health service utilization, and prescription drug claims from a selection of insured individuals of large employers and private health plans. Among patients newly started on buprenorphine for OUD in federal fiscal year 2011 (FY 2011) and followed up through FY 2014, we examined the duration of buprenorphine treatment up to and beyond three years along with correlates, including sociodemographic and diagnostic characteristics, health service and psychotropic medication use, and insurance disenrollment. These data thus broaden the picture of the challenges facing efforts to increase buprenorphine treatment retention among patients with OUD.
Discussion
In this study of a large privately insured cohort of patients initiated on buprenorphine for OUD in FY 2011, fewer than half were retained in treatment for more than one year and fewer than 15% for more than three years. Nearly half of the patients who initiated buprenorphine treatment disenrolled from their insurance plan in the next three years, and this was one of the stronger correlates of treatment disengagement. Mental health inpatient admissions and emergency room visits also predicted early treatment disengagement, whereas older age and receipt of psychotherapy in the year of buprenorphine initiation were associated with lower risk of treatment disengagement.
Buprenorphine treatment retention in this study (45.0% at one year) is similar to that reported in prior studies of commercially insured populations (
24–
27) but considerably lower than that observed at VHA facilities (61.6% with comparable methods) (
21) and also considerably lower than that in a statewide public initiative in Massachusetts (65%) (
37). Most important, VHA patients experienced no risk of disenrollment from their health care plan. In addition, compared with patients with commercial insurance, they were a decade older, had greater access to comprehensive care for substance use disorders, and were likely to have far lower copays (
38,
39). Higher age, a consistent predictor of better buprenorphine treatment retention (
21,
40–
43), may also have contributed to better retention in the VHA. However, in the Massachusetts study that showed high retention (
37), the age distribution was similar to that in the study reported here. In addition, patients with more severe mental health issues may seek more care, especially in the VHA system, where mental health care is relatively accessible at little or no cost (
44).
Both the VHA and the Massachusetts studies followed well-supported comprehensive systemwide buprenorphine implementation efforts (
37,
45), which are often unavailable in outpatient practices funded by commercial insurance. Offering comprehensive psychosocial care for patients with OUD, along with buprenorphine treatment, may help providers funded by commercial insurance improve buprenorphine treatment retention (
24,
25).
We are not aware of prior studies that addressed continuity of insurance coverage as a factor in continued buprenorphine treatment in a commercially insured population (
24–
27). This is not an issue in the VHA, where entitlement is based on past military service, and this may largely explain the higher VHA retention rates. The association of continued insurance coverage with buprenorphine treatment retention is impressive and worrisome during this period of changes in health care laws and policies. OUD is a chronic disease that can have disastrous consequences without long-term treatment (
46). Our data suggest that unavailability of buprenorphine treatment with loss of insurance coverage (which may itself result from continued opiate use) poses a major threat to effective treatment. Further studies are needed to identify the reasons for loss of insurance coverage among adults with OUD and whether OAT is continued in some cases through other types of financing.
In addition, insurance plans typically impose significant out-of-pocket costs and burdensome requirements for prior authorizations for buprenorphine, posing significant barriers to continued engagement. Although commercial insurance plans were not excluding buprenorphine by 2010, most plans still included buprenorphine in the high cost-sharing tiers, and 38% of the plans required preapproval, substantially higher than in 2003 (7%) (
47,
48). Insurance plans also restrict the duration of buprenorphine treatment, especially in managed Medicaid plans, and demand onerous counseling requirements (
49,
50). The effects of the Affordable Care Act that were intended to increase accessibility to substance abuse treatments are still evolving and implementation of the ACA, while currently (2017) in jeopardy, differs across participating states (
51). These data suggest that although access to buprenorphine has increased over the past decade (
6,
10–
15), there are still multiple financial barriers. Despite such barriers, patients with high motivation and financial means seem to be accessing buprenorphine treatment (
50). The highly restrictive response to the opioid crisis among payers is of concern and deserves more detailed study and documentation.
Altogether, 26.3% of privately insured patients with a diagnosis of OUD initiated buprenorphine in the index year, compared with only 6% initiation of OAT, including buprenorphine (3.4%), in VHA in FY 2012 (unpublished data available on request). The reasons for differences in initiation rates likely involve major differences in case finding, eligibility, enrollment, and diagnostic documentation procedures. In addition, while the vast majority of buprenorphine in the VHA is provided through specialized substance abuse treatment clinics (
45,
52), buprenorphine provision among privately insured patients is mostly through office-based, nonpsychiatrist physicians (
27), who are generally more permissive of buprenorphine prescription than psychiatrists (
53). Also, VHA providers do not have the financial incentives that play a prominent part in increasing buprenorphine prescription in non-VHA settings (
54,
55). VHA is currently implementing programs to increase access to buprenorphine in primary care settings.
This is the first major, large-scale observational study to specifically examine the association of receipt of psychotherapy with buprenorphine treatment retention; both psychotherapy and buprenorphine are perceived as essential components of comprehensive OUD treatment (
4). However, the need for psychotherapy or formal counseling with buprenorphine treatment is unclear (
56). Psychotherapy or formal counseling yielded no additional benefits over standard physician counseling with regard to illicit opioid use, abstinence, or treatment retention in many recent buprenorphine clinical trials (
57–
60), whereas other studies have demonstrated added benefit (
61–
64). Our observational study suggests that receipt of psychotherapy in the first year of treatment was associated with greater retention. This might be a direct effect of psychotherapy, although it may also reflect a selection bias that is not accounted for by the variables available in the study (that is, patients with a better chance of sustained retention might have been selected for or chosen to receive psychotherapy).
Although the proportion of patients with psychiatric disorders was lower in the commercially insured population than in the VHA population (
21), psychiatric disorders and their severity, as reflected in emergency room visits and mental health inpatient admissions, were associated with lower retention. Unlike the VHA study, which involved an older population (
21), this analysis of data from a younger sample of patients showed that older age reduced the risk of dropout.
The data in this study are observational, which limits causal conclusions about determinants of buprenorphine treatment retention. We lacked data on several factors that have been shown to effect treatment retention, including duration and severity of OUD, type of opioid abused, certain psychosocial factors, nature and duration of treatment interruptions, adherence, and loss of patients because of death (
20,
24,
25). As in the previous VHA-based study (
21), we did not have information on the reasons for discontinuation. It is possible that a proportion of patients successfully tapered off buprenorphine with complete resolution of their OUD, although prior studies have suggested that most discontinuations likely represent premature treatment dropout, with a high risk of relapse (
33,
65,
66). Although only outpatient prescriptions were included in the study, we cannot completely exclude the possibility that a proportion of buprenorphine disengagement in the first 30 days occurred after short-term “detox.” In addition, buprenorphine treatment can be influenced by physician characteristics, such as attitudes toward buprenorphine, and by organizational support (
67–
70). We also lacked information about whether patients disengaged from treatment first and then disenrolled from insurance (perhaps because of relapse and job loss), lost insurance first and discontinued treatment as a result, or received treatment from other sources after disengagement.