Association of Medicaid-Focused or Commercial Medicaid Managed Care Plan Type With Outpatient and Acute Care.

Importance: Enrollment in Medicaid managed care plans has increased rapidly, particularly in national commercial insurance plans. Whether the type of managed care plan is associated with the use of health services for Medicaid beneficiaries is unknown. Objective: To compare the use of outpatient and acute care between Medicaid enrollees randomly assigned to a national commercial managed care plan or a local Medicaid-focused managed care plan. Design, Setting, and Participants: This natural experiment of a cohort of Medicaid enrollees randomly assigned to 2 managed care plans in a Northeastern US state was conducted from June 30, 2009, to June 30, 2013. Statistical analysis was performed from September 1, 2019, to August 30, 2020. Interventions: Assignment to a Medicaid-focused insurance plan or a commercial managed care plan. Main Outcomes and Measures: Outpatient visits, emergency department visits, and total inpatient and ambulatory care-sensitive hospitalizations. Results: A total of 8010 patients were included in the analysis: 4737 were assigned to a Medicaid-focused plan (2795 female [59.0%]; mean [SD] age, 17.8 [3.2] years) and 3273 to a commercial managed care plan (1915 female [58.5%]; mean [SD] age, 17.9 [3.3] years). Those randomly assigned to the Medicaid-focused plan had a mean (SD) of 6.67 (9.18) annual outpatient visits per person, and those assigned to the commercial plan had a mean (SD) of 8.36 (11.77) annual outpatient visits per person (adjusted absolute difference, 1.72 [95% CI, 1.31-2.13]; 22% relative difference). The increased use of outpatient visits in the commercial plan was associated with an increase in specialty care visits (mean [SD], 2.34 [6.31] visits in Medicaid-focused plan vs 3.75 [9.32] visits in commerical plan; adjusted absolute difference, 1.43 visits [95% CI, 1.25-1.56 visits]; 61% relative difference). Mean (SD) annual emergency department visits were 0.49 (1.39) per person in the Medicaid-focused plan and 0.51 (1.40) in the commercial plan (adjusted absolute difference, 0.02 [95% CI, -0.02 to 0.05]). Mean (SD) annual inpatient admissions were 0.067 (0.45) per person in the Medicaid-focused plan and 0.069 (0.53) in the commercial plan (adjusted absolute difference, 0.003 [95% CI, -0.01 to 0.02]). Plan assignment was not significantly associated with ambulatory care-sensitive admissions. Results were consistent in instrumental variables analyses that accounted for disenrollment and switching. Conclusions and Relevance: Compared with Medicaid managed care enrollees assigned to a Medicaid-focused plan, those assigned to a commercial plan had more outpatient visits, particularly for specialty care, but had similar rates of emergency department visits and hospitalizations. These findings suggest that the type of managed care plan may be associated with health services use and spending among Medicaid beneficiaries and that random assignment may help states understand how well different plans perform for enrollees.