Association of the Affordable Care Act Medicaid Expansion with Dilated Eye Examinations among the United States Population with Diabetes

Abstract

Purpose: To evaluate the association between Medicaid expansion and diabetic dilated eye examinations.

Design: A retrospective difference in differences (DiD) analysis using individual-level survey response data from January 1, 2009, to December 31, 2017.

Participants: A total of 52 392 survey responses from 50 states and the District of Columbia between 2009 and 2017. Responders were adults aged 18 to 64 years reporting a previous diagnosis of diabetes and a household income below 138% of the US federal poverty line (FPL).

Methods: The Centers for Disease Control and Prevention's Behavioral Risk Factor Surveillance System data were used to identify survey responders who were asked about the presence of dilated eye examinations from years before and after Medicaid expansion implementation.

Main outcome measures: The DiD in proportion of dilated eye examinations among diabetic persons aged 18 to 64 years with household incomes below 138% of the FPL between states that did and did not implement Medicaid expansion.

Results: Implementation of Medicaid expansion policies was associated with a 1.3% (95% confidence interval [CI], -3.8 to 6.4; P = 0.61), 6.3% (95% CI, 1.3-11.3; P = 0.016), 4.1% (95% CI, -0.8 to 9.0; P = 0.11), and 2.3% (95% CI, -1.6 to 6.2; P = 0.23) increase in the proportion of diabetic persons aged 18 to 64 years with incomes below 138% of the FPL receiving a dilated eye examination within the past year due to Medicaid expansion 1, 2, 3, and 4 cumulative years after expansion, respectively.

Conclusions: Medicaid expansion policies were significantly associated with an increase in dilated eye examination rates within the first 2 years after implementation. However, this increase did not persist beyond this period, with nonsignificant increases 3 and 4 cumulative years after implementation. Healthcare policymakers should be aware that additional measures beyond expanding insurance coverage may be necessary to increase and sustain the rate of dilated eye examinations among diabetic populations.