Geographic variations and facility determinants of acute care utilization and spending for ACSCs.

Objectives: To compare rates and analyze health facility determinants of emergency department visits and hospitalizations for ambulatory care-sensitive conditions (ACSCs) among Medicaid patients by geographical location.

Study design: Retrospective cross-sectional analysis of 48.3 million patients receiving Medicaid and their acute care visits across 34 states and the District of Columbia in 2019.

Methods: Descriptive analyses of county-level variations in emergency department visits and hospitalizations (acute care) for ACSCs, and multivariate regressions of proximity to and density of health facility infrastructure as correlates to utilization and spending. Regression models were adjusted for county-level poverty rates, chronic disease rates, and state fixed effects.

Results: Among the studied patient population receiving Medicaid, nearly 40% of acute care visits were for ACSCs, with variations across and within states. Rates ranged from 17.8 per 1000 member-months in Vermont to 39.0 in Mississippi, and from 5.9 to 77.9 between counties within states. Longer distances to the nearest urgent care center and primary care shortage area designation correlated to higher acute care visits for ACSCs (+4.3 per 1000 member-months for every 100 miles; 95% CI, 2.9-5.7; P < .001; +1.5 per 1000 member-months if shortage area; 95% CI, 0.4-2.6; P = .006). Counties with more rural health clinics had fewer acute care visits for ACSCs (-3.4 fewer visits per rural clinic per 1000 population; 95% CI, -4.6 to -2.2; P < .001). Among 6 states with additional spending data, 4.2% of total Medicaid spending was attributable to acute care visits for ACSCs.

Conclusions: Our evaluation revealed more than 13-fold variation in acute care utilization for ACSCs between Medicaid counties within the same state. Proximity to urgent care facilities and density of rural health clinics were major explanatory variables for these variations, underscoring the importance of local health infrastructure in reducing acute care utilization for ACSCs.