Neighborhood Socioeconomic Disadvantage and Acute Care Utilization in Washington State Medicaid: A Retrospective Cohort Study

Background: Neighborhood disadvantage has been associated with potentially preventable acute care utilization among Medicare beneficiaries, but this association has not been studied in a Medicaid population, which is important for informing more equitable care and policies for this population.

Objective: To describe the association between Area Deprivation Index (ADI) and acute care utilization (including potentially preventable utilization) among Medicaid beneficiaries in Washington State.

Design: Retrospective cohort study of 100% Medicaid claims. Mixed effects logistic regression was applied to estimate the association between state-level ADI decile and acute care utilization, adjusting for age, sex, self-identified race and ethnicity, Charlson Comorbidity Index, primary spoken language, individual Federal Poverty Level, homelessness, and rurality. Standard errors were clustered at the Census block group level.

Participants: 1.5 million unique adult Medicaid beneficiaries enrolled for at least 11 months of a calendar year during the period 2017-2021.

Main measures: Binary measures denoting receipt of ED visits, low-acuity ED visits, hospitalizations in a calendar year.

Key results: Increasing levels of neighborhood socioeconomic disadvantage (by ADI decile) were associated with greater odds of any ED visits (adjusted odds ratio (aOR) 1.07, 95% confidence interval (CI) 1.06-1.07), low-acuity ED visits (aOR 1.08, CI 1.08-1.08), and any hospitalizations (aOR 1.02, CI 1.02-1.02).

Conclusions: Among Medicaid beneficiaries, greater neighborhood socioeconomic disadvantage was associated with increased acute care utilization, including potentially preventable utilization. These findings signal potential barriers to outpatient care access that could be amenable to future intervention by health systems and payers.