Assessing the Impact of Parity for Substance Abuse Treatment on Healthcare Utilization

According to the Substance Abuse and Mental Health Services Administration (SAMHSA), in 2012, 8.5% of Americans over the age of twelve were classified as having a substance use disorder (SUD). Of those with a SUD, roughly one in 10 received treatment, constituting a substantially low uptake of services. Many who did not receive treatment blamed their inability to pay for treatment services and a lack of insurance coverage, signaling that a policy designed to expand coverage for SUDs would increase treatment utilization.

The Paul Wellstone and Pete Domenici Mental Health Parity and Addiction Equity Act of 2008 (MHPAEA) required that all group health plans covering “large employers”, Medicaid managed care organizations (MCOs), and the Children’s Health Insurance Program (CHIP) provide parity between medical/surgical benefits and mental health and substance use disorder (MHSUD) benefits. It was the first federal law to introduce parity of benefits for substance abuse. On January 1, 2014, the Affordable Care Act (ACA) will further extend the scope of parity by requiring Medicaid non-managed care benchmark and benchmark-equivalent state plans, qualified health plans established by the ACA, and individual and small group plans sold on the Healthcare Exchange to be parity compliant. These plans will also be required to provide ten “essential health benefits” including coverage for MHSUD services. Understanding how the MHPAEA affected healthcare utilization for SUDs will help us predict the impact of the ACA’s expansion of parity.

Much of the current literature aimed at assessing the impact of the MHPAEA and ACA legislation relies on the effects of state-level parity legislation enacted prior to the MHPAEA to predict how Federal parity laws will influence utilization of SUD services (Dave, et al. 2011; Wen, et al. 2013; McConnell, et al. 2012). However, self-funded group plans, which cover approximately 59% of individuals with employer sponsored insurance and 69% of workers receiving coverage from large employers, are regulated by the Employee Retirement Income Security Act (ERISA) and were not required to comply with state parity laws, limiting the generalizability of results from these studies.

Unlike previous studies, this research will determine if the introduction of a federal, comprehensive parity law led to changes in the utilization of SUD services and/or emergency department admissions for drug misuse and abuse. This will be accomplished by utilizing data collected by SAMSHA before and after the MHPAEA went into effect on January 1, 2010, that includes SUD treatment admissions from the Treatment Episode Dataset (TEDS) and admissions to emergency departments (ED) for drug misuse and abuse from the Drug Abuse Warning Network (DAWN). If the MHPAEA was effective in increasing access to SUD treatment we would expect treatment admissions to increase and result in fewer ED admissions for drug abuse. However, a preliminary, descriptive analysis suggests that after the MHPAEA was implemented ED admissions increased slightly while SUD treatment admissions slightly declined. Next, I will be conducting a multivariate regression analysis to assess if the MHPAEA had the expected effects on utilization, despite these preliminary trends.