Use of Hospital-Based Services Among Young Adults With Behavioral Health Diagnoses Before and After Health Insurance Expansions

The coverage and financing of health care services for individuals with mental illness and substance use disorders are changing rapidly in the U.S. The 2008 Federal parity legislation requires that insurance benefit design and management for mental health and substance abuse treatment match those for medical and surgical services. The 2010 Patient Protection and Affordable Care Act (PPACA), with coverage provisions mirroring Massachusetts’ 2006 health reform,1 expands health insurance coverage to populations with high behavioral health needs through Medicaid expansions,2,3 establishes health insurance exchanges to ease purchase of individual and small group health insurance, and requires that insurers permit dependent children to remain on parental insurance policies to age 26. Furthermore, PPACA requires health plans offered through new insurance exchanges to cover mental health and substance abuse treatment, and other PPACA reforms integrate care across settings for behavioral health treatment.4 Most behavioral health disorders, 75%, emerge by age 24,5 and the odds of having a 12-month DSM IV disorder are higher for individuals age 18 to 29 than any other adult age group.6 Despite the long-term mortality, disability, and labor market consequences of these disorders,7,8 young adults lack health insurance coverage more often than other age groups.9 The lack of coverage is particularly important for young adults in foster care, child Supplemental Security Income recipients, and Medicaid recipients, for whom the 18th birthday coincides with a loss of benefits.10,11 In outpatient settings, demand for behavioral health treatment is more responsive to insurance coverage and patient cost sharing than other health care services, suggesting that hospital-based services may rise in response to increased insurance coverage.12,13 Alternatively, hospital-based services may fall with increased insurance coverage either because outpatient care use substitutes for inpatient care, or due to utilization management of managed behavioral health organizations responsible for new enrollees.14 Little is known about behavioral health service use when young adults acquire coverage. In this paper, we study the experience of the Massachusetts health reform to examine inpatient hospital admissions and emergency department visits for young adults aged 19 to 25 diagnosed with behavioral health disorders. To understand how utilization of hospital-based care, and insurance coverage for such care changed following health insurance coverage expansion, we compared inpatient admissions before and after 2006 in Massachusetts to the rest of the US. We further compared these differences among the 19 to 25 year olds to differences among adolescents aged 12 to 18 in Massachusetts, for whom insurance coverage changed less after health reform.15 To examine changes in emergency department (ED) visits, we use a similar approach, focusing on the universe of ED visits in Massachusetts and Maryland. We estimated the net effect of opposing influences of insurance coverage on hospital-based behavioral health services against a null hypothesis that service use would not change after coverage expanded.