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Putting Parity to the Test


"When you have inequities in insurance coverage, it contributes to the idea that there’s something wrong with seeking treatment for mental illness or substance use disorders.”

THE PAUL WELLSTONE AND PETE DOMENICI Mental Health Parity and Addiction Equity Act of 2008 (MHPAEA) was heralded as a landmark law with the potential to dramatically improve access to mental health and substance use treatment in the United States. Requiring commercial health plans that offer such benefits to provide them on par with medical and surgical benefits, the new law went further than any policy before it in its effort to ensure that more people who need mental health and substance use services are able to get them.

“There is a long history of inequities in insurance coverage for medical care vs. coverage for behavioral health care, including treatment for both mental illness and substance use disorders,” says Dr. Susan Ettner, a professor in FSPH’s Department of Health Policy and Management. “Earlier laws had tried to address those disparities, including one previous federal parity law and a number of state parity laws. But all of those policies had limitations that led to the persistence of the inequities.”

MHPAEA promised to be different, and now Ettner, an economist with an interest in how policies aiming to change financial incentives can influence health services utilization and outcomes, is in the midst of a federally funded effort to determine whether it’s fulfilling that promise. She heads a four-year, National Institute on Drug Abuse-funded study that uses administrative data from Optum, the nation’s largest managed behavioral health organization, to address key questions related to how MHPAEA is affecting the coverage, utilization and cost of mental health and substance use services.

MHPAEA’s provisions went beyond previous federal and state parity legislation in important ways, Ettner says. Self-funded insurance plans – an increasingly popular option among large employer groups – are exempt from any benefit mandates coming from states, but as a federal law, MHPAEA was able to apply to such plans, ensuring that far more people would be affected. The new law is also much more comprehensive than anything before in the way it mandates parity in three key aspects of coverage: financial requirements, including co-payments and deductibles; quantitative treatment limits, including maximum number of outpatient visits or inpatient nights covered; and, perhaps most significantly, non-quantitative treatment limits – including medical necessity reviews, prior authorization requirements, and other stipulations that can be used to limit coverage. In addition, unlike the previous federal law and many state mandates, MHPAEA applies to substance use disorders as well as mental health diagnoses.

Among the fundamental concerns Ettner’s study addresses is whether MHPAEA might have the unintended effect of reducing access to mental health and substance use services. “The law doesn’t require that plans cover a mental health or substance use diagnosis; it just says that if they do cover it, they have to cover it at parity with medical care,” Ettner says. “Our concern was that some employer groups, rather than offering more generous coverage of behavioral health disorders, might choose not to cover these diagnoses at all. But we haven’t found any evidence that employer groups are dropping coverage for behavioral health.”

The study is also exploring the impact on mental health and substance use benefits offered by employers that do continue to cover them under the parity law. “We expected that cost-sharing would decline; that the quantitative treatment limits would either be eliminated or would become more generous, depending on what was happening on the medical side; and that the non-quantitative treatment limits – in other words, the direct management of care – would be relaxed,” Ettner says. “And if all that occurred and the benefits did become more generous, you would expect to see greater utilization and expenditures for the services, along with a shift of costs away from the patient and toward the plan.”

Thus far, Ettner and her study colleagues are finding some positive changes in all of these areas. Most striking, Ettner notes, are the changes in quantitative treatment limits. “Before parity, it was very common for a health plan to place limits on the number of inpatient nights or outpatient visits, which meant that anyone who was a high utilizer of services was going to run up against the limit, at which point coverage stopped,” she says. “Post-parity law, this has been completely eliminated. We have found that consistently across different types of plans.”

By partnering with Optum – which contracts with more than 3,000 employers, health plans and public sector agencies, covering nearly 25 million people across all 50 states – Ettner has access to the company’s administrative data, which is more reliable for analysis than data that would be obtained from surveying members, who are often uncertain about the nature of their benefits. At the Fielding School, Ettner is partnering on the research with her doctoral student, Sarah Friedman, who is using the same data to write her dissertation about how members’ utilization of mental health services is affected by the changes in benefit features before and after the parity law. “Given the important role mental health plays in maintaining overall health, as well as helping individuals enjoy productive and fulfilling lives, there are so many important questions to explore. I hope to pursue future research that informs policy and practice in this arena,” Friedman says.

For all of its strengths, MHPAEA doesn’t fully solve the issue of access to appropriate mental health and substance use disorder services, Ettner says. Although removal of the treatment limits is important for patients with the most severe needs, most people never hit their limits. The law doesn’t require that plans cover specific disorders, and applies only to commercially insured, large-employer groups. “We don’t want to lose sight of the fact that the sickest of the sick tend to be publicly insured or uninsured individuals, who are not affected by this law,” Ettner says. “And unfortunately, public services tend to be underfunded and mentally ill and substance abusing populations lack political clout.” However, she notes, provisions under the Affordable Care Act will extend the reach of the parity provisions to many of these vulnerable patients in the future.

Nonetheless, she believes that the law represents a milestone – not only by increasing access for a large population of individuals in need of the services, but because of the message it sends. “An issue that always arises with behavioral health care is stigma,” Ettner says. “When you have inequities in insurance coverage, it contributes to the idea that there’s something wrong with seeking treatment for mental illness or substance use disorders. This law makes a statement that these are illnesses that need treatment, just like any other medical condition.”