Effect of Medicaid Disenrollment on Health Care Utilization Among Adults With Mental Health Disorders.

Background: Medicaid is an important source of insurance coverage for those with mental health (MH) disorders in the United States. Although disruptions in Medicaid coverage are common, little is known about the dynamic relationship between Medicaid disenrollment and MH care utilization.

Objective: We estimated changes in all-cause and MH-related health care use post Medicaid disenrollment among a nationwide cohort of adults with MH disorders. Subjects: We identified 8841 persons (197,630 person-months) ages 18-64 with MH disorders and Medicaid coverage from Panels 4 to 19 Medical Expenditure Panel Survey.

Methods: Using a quasi-experimental design and propensity weighting, we estimated logit models examining changes in service utilization per-person-per-month. We used a "post" indicator to estimate average differences in service use postdisenrollment (vs. those with continuous Medicaid coverage) and a count variable measuring total months since coverage loss to estimate changes over time. Outcome measures: All-cause outpatient visits, MH-related outpatient visits, and acute care visits.

Results: Becoming uninsured after Medicaid disenrollment was associated with average reductions of 52% [-14.75 percentage-points, 95% confidence interval (CI): -17.59, -11.91] in the likelihood of receiving any outpatient service, 35% (-2.23 percentage-points, 95% CI: -3.71, -0.75) in the likelihood of receiving any MH-related outpatient service, and 52% (-2.44 percentage-points; 95% CI: -3.35, -1.52) in the likelihood of receiving any acute service in a month. Health care use declined the most in the month immediately postdisenrollment, and declines continued over the next half-year (while uninsured).

Conclusions: Insurance loss after disenrollment from Medicaid led to a persistent disruption in the receipt of health care services for beneficiaries with MH disorders.