Online Program

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Tuesday, January 7
Tue, Jan 7, 11:00 AM - 12:45 PM
Porthole
Health Policy Methods for Medicare and Medicaid

Using Marginal Structural Models to Estimate the Effect of the Maryland Medicaid Health Home Waiver on Health Care Utilization Among Individuals with Serious Mental Illness (307852)

*Sachini Bandara, Johns Hopkins Bloomberg School of Public Health 
Colleen Barry, Johns Hopkins Bloomberg School of Public Health 
Gail Daumit, Johns Hopkins School of Medicine 
Alene Kennedy-Hendricks, Johns Hopkins Bloomberg School of Public Health 
Beth McGinty, Johns Hopkins Bloomberg School of Public Health 
Elizabeth Stuart, Johns Hopkins Bloomberg School of Public Health 

Keywords: marginal structural model, serious mental illness, Medicaid, care coordination

The Maryland Medicaid health home program, established through the Affordable Care Act, integrates primary care services into specialty mental health programs for adults with serious mental illness (SMI). We evaluated the effect of this waiver program on all-cause, somatic, and behavioral health emergency department (ED) and inpatient utilization. To account for time-varying confounding introduced by rolling enrollment into the program, we used a marginal structural model estimated with inverse probability of treatment weighting. We analyzed Maryland Medicaid administrative claims data for 12,203 enrollees with SMI over a 39-month period (October 1, 2012-December 31, 2016); 3,293 individuals were enrolled in a BHH and 8,911 were never enrolled. Health home enrollment was associated with reduced probability of all-cause (23% vs. 25% within 3 months, p<0.01) and somatic ED visits (21% vs. 24%, p<0.01). We discuss study implications, as well as opportunities and challenges of broader use of marginal structural models in health policy.