Discontinuity of Medicaid Coverage: Impact on Cost and Utilization Among Adult Medicaid Beneficiaries With Major Depression.

BACKGROUND: Gaps in Medicaid coverage may disrupt access to and continuity of care. This can be detrimental for beneficiaries with chronic conditions, such as major depression, for whom disruptions in access to outpatient care may lead to increased use of acute care. However, little is known about how Medicaid coverage discontinuities impact acute care utilization among adults with depression.
OBJECTIVE: Examine the relationship between Medicaid discontinuities and service utilization among adults with major depression.
SUBJECTS: A total of 139,164 adults (18-64) with major depression was identified using the 2003-2004 Medicaid Analytic eXtract Files.
METHODS: We used generalized linear and two-part models to examine the effect of Medicaid discontinuity on service utilization. To establish causality in this relationship, we used instrumental variables analysis, relying on exogenous variation in a state-level policy for identification. OUTCOME MEASURES: Emergency department (ED) visits, inpatient episodes, inpatient days, and Medicaid-reimbursed costs.
RESULTS: Approximately 29.4% of beneficiaries experienced coverage disruptions. In instrumental variables models, those with coverage disruptions incurred an increase of $650 in acute care costs per-person per Medicaid-covered month compared with those with continuous coverage, evidenced by an increase in ED use (0.1 more ED visits per-person-month) and inpatient days (0.6 more days per-person-month). The increase in acute costs contributed to an overall increase in all-cause costs by $310 per-person-month (all P-values<0.001).
CONCLUSIONS: Among depressed adults, those experiencing coverage disruptions have, on average, significantly greater use of costly ED/inpatient services than those with continuous coverage. Maintenance of continuous Medicaid coverage may help prevent acute episodes requiring high-cost interventions.