Three Studies on Mental Health Implications of Discontinuous Insurance Coverage and Medicaid Eligibility Policies Open Access

Ji, Xu (2017)

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Medicaid is the largest insurer of mental health services; however, little is known about how the instability of Medicaid coverage affects patients with mental disorders. This dissertation comprises two studies examining the effects of Medicaid coverage instability on healthcare services delivered in acute care and outpatient settings and one study examining how state eligibility polices impact Medicaid continuity and service utilization for this vulnerable population.

The first study examines the impact of Medicaid discontinuities on acute care utilization among adult beneficiaries with major depression. To establish causality between coverage discontinuities and acute service use, I use an instrumental variables (IV) approach that addresses the sources of endogeneity in this relationship. I found that those experiencing coverage disruptions have, on average, significantly greater use of costly emergency department/inpatient services than those with continuous coverage.

In the second study, I evaluate the impact in two Southern states of Express Lane Eligibility (ELE) - a state-specific policy that streamlines children's eligibility recertification procedures - on coverage continuity and acute care utilization among Medicaid-insured children with depression. Using difference-in-difference analysis, I found substantial heterogeneity in ELE effects across these two states. While ELE in Louisiana generally had no effects, Alabama's implementation of ELE significantly reduced coverage disruptions and use of acute care for mental disorders.

The third study examines the impact of losing Medicaid coverage on outpatient service utilization among low-income adults with mental illness. Using national panel data and an IV approach to address key sources of endogeneity, this study provides evidence for a remarkable reduction in outpatient service use immediately after losing Medicaid with no alternative source of coverage. The results, however, do not lend support for a significant effect on outpatient care use among those who transition from Medicaid to private plans.

Combined, the three studies provide new information about the implications of insurance coverage discontinuities among Medicaid populations with mental health disorders, and about the importance of state policies aimed at streamlining eligibility recertification processes to increase Medicaid retention rates, improve access to healthcare and chronic condition management, and ultimately advance health outcomes among vulnerable populations with high need.

Table of Contents


I. Background. 1

II. Introduction to Study 1: Discontinuity of Medicaid Coverage: Impact on Cost and Utilization among Adult Medicaid Beneficiaries with Major Depression. 9

III. Introduction to Study 2: Express Lane Eligibility, Medicaid Coverage, and Acute Care Use among Children with Depression in Two Southern States. 12

IV. Introduction to Study 3: The Impact of Medicaid Churning on Healthcare Utilization Among Adults with Mental Health Disorders. 14

References. 20


Abstract 34

I. Introduction. 35

II. Methods. 37

III. Results. 42

IV. Discussion. 45

V. Conclusion. 49

References. 50

Appendix. 61


Abstract 65

I. Introduction. 66

II. Background. 68

III. Methods. 71

IV. Results. 78

V. Discussion. 81

VI. Conclusion. 85

References. 86

CHAPTER 4. 100

Abstract 100

I. Introduction. 101

II. Methods. 104

III. Results. 113

IV. Discussion. 118

V. Conclusion. 122

References. 124

Appendix. 139

CHAPTER 5. 142

References 146

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