Access to evidence-based treatment for opioid use disorder can be shaped by the policies governing how care is funded and delivered. In a recent study, researchers from Temple University Barnett College of Public Health examined whether Section 1115 IMD waivers affected the use of medications for opioid use disorder (MOUD) in residential treatment settings, and whether those effects varied depending on when states adopted the waivers.
Dr. Pricila Mullachery is an interdisciplinary scholar with a background in health disparities, policy analysis, and causal inference. Her research focuses on how laws and policies affect health among disadvantaged populations in complex public health issues related to the opioid crisis, access to evidence-based interventions, and the burden of chronic non-communicable diseases.
We spoke with Dr. Mullachery about what motivated the research, how the timing of state policy adoption affected the findings, and what these results may mean for policymakers and public health professionals.
CPHLR: What motivated your team to examine the relationship between Section 1115 IMD waivers and the use of MOUD in residential treatment settings?
Dr. Mullachery: Our primary motivation was to understand how Medicaid policies influence access to and quality of care available to socially disadvantaged people with substance use disorders. Section 1115 waivers allow states to test new approaches, including covering services not typically covered by Medicaid; these waivers have been used to expand access to populations and services since before the Affordable Care Act. States may or may not apply for a waiver; so they present an opportunity to measure the impact of various policies.
Section 1115 IMD waivers, in particular, were designed to expand treatment to Medicaid beneficiaries with substance use disorders by allowing states to use federal dollars to cover services in residential facilities known as Institutions for Mental Diseases or IMDs. Medicaid legislation originally prohibited the use of federal funds to cover services in these residential facilities. But in 2015, the Centers for Medicare & Medicaid Services (CMS) began accepting proposals from states to waive this provision via the 1115 waiver. In this new paper, we sought to examine whether the adoption of these waivers by states had an impact on access to evidence-based treatment.
CPHLR: How does this research contribute to the broader body of evidence examining how state and federal policies shape access to evidence-based treatment for opioid use disorder?
Dr. Mullachery: The evidence on the impact of IMD waivers is mixed. The existing literature shows that in states that adopted a waiver, residential facilities are more likely to accept Medicaid as a form of payment. Before-and-after single-state studies show that IMD waiver adoption was associated with fewer emergency department visits. But multi-state studies have not shown a significant impact of IMD waivers on MOUD, the most effective treatment available to reduce overdose risk. Residential facilities generally have lower MOUD utilization rates, compared to other treatment settings. Increasing access to MOUD is one of the objectives of 1115 waivers, although specific goals and implementation features may vary across states. Our study provides additional evidence and raises other questions about how 1115 waivers may shape access to MOUD. Specifically, we found that IMD waivers led to increased MOUD use in residential facilities, though this effect was observed only in early cohorts, i.e., states that adopted the waiver in 2016-2017.
CPHLR: Your study examines states across different IMD waiver adoption cohorts. Why was it important to consider the timing of waiver adoption in your analysis?
Dr. Mullachery: A central question of this paper was whether different adoption timing might lead to different outcomes. IMD waivers evolved over time; the first CMS guidance was issued in 2015, with only a few states initially applying under this guidance. In November 2017, a second CMS guidance was issued, and a greater number of states applied for a waiver between 2018 and 2019. We hypothesized that changes in guidance issued under different federal administrations could lead to waiver variation with potentially different impacts. That was the main reason to examine cohort-specific effects in this paper. Indeed, we found meaningful variation across cohorts: Compared with states without waivers, early adopter states experienced an increase in MOUD use, whereas states that adopted a waiver under the post-2017 guidance did not. Our future work will examine potential explanations for that variation. One of the hypotheses is that waiver design and components may vary substantially across states and over time.
CPHLR: What did you find most interesting or surprising about MOUD use in residential and non-residential treatment settings?
Dr. Mullachery: Our study showed that MOUD use in residential facilities was much lower than in non-residential facilities. This was not necessarily surprising because it is consistent with previous studies. But we also saw that MOUD use increased substantially in residential facilities during the study period, reducing the gap between residential and non-residential settings. This narrowing of the gap can be seen in a simple trend figure (Figure 1 in our paper). Our adjusted models also show that non-residential MOUD use did not increase in waiver states relative to non-waiver states. This finding supported the hypothesis that IMD waivers improved access to MOUD only in residential facilities, which were the target of the policy.
Figure 1. MOUD use in residential and non-residential treatment settings
CPHLR: What do you hope policymakers and public health professionals take away from these findings?
Dr. Mullachery: We hope that policymakers and public health professionals recognize that the design and implementation of policies matter. Our findings suggest that IMD waivers may improve access to MOUD in residential facilities, but the effects were not consistent across all states and adoption cohorts. Policymakers should continue to support efforts to integrate MOUD in residential settings while examining which features, resources, and implementation strategies are most effective.
CPHLR: As you look ahead, what are the next steps in your research, and what questions do you think the field still needs to explore?
Dr. Mullachery: Looking ahead, we are examining specific features of IMD waivers and how they vary across states and over time. We are using legal epidemiology methods to describe key features of the IMD waiver policy. We are also interested in differences between policy on the books and policy in action, state context, implementation strategies and timing, and how these factors may contribute to variation in the expected policy effect at the population level.