Effects of the Affordable Care Act and Medicaid Expansion on Incident End-Stage Renal Disease Patients

Enacted in 2010 and largely implemented in 2014, the Affordable Care Act (ACA) has expanded health insurance coverage to more than 20 million previously uninsured American adults through the Medicaid expansions implemented by 31 states and health insurance exchanges on which individuals can purchase insurance and received subsidies if their incomes are between 100% and 400% of the Federal Poverty Level. While nearly all Americans with end-stage renal disease (ESRD) have insurance after the onset of this condition, those who are uninsured may not have access to effective care before developing ESRD. We assess whether changes in insurance status prior to the onset of ESRD were accompanied by changes in markers of pre-ESRD care in patients receiving their first dialysis treatment pre-enactment of the ACA versus post-enactment of the ACA. We use data from the CMS Medical Evidence Form 2728 which is completed for all patients at incidence of ESRD. This included 511,424 patients from 10/1/11 to 3/31/16. We estimate Difference-in-Differences (D-in-D) models by age/insurance status at ESRD onset [age <65 with no Medicare (treatment group) vs. age ≥ 66 with Medicare (control group)], and by state Medicaid expansion status for age <65 [States expanding Medicaid (treatment group) vs. states not expanding Medicaid (control group)]. Using linear probability models, we determine the ACA’s impact on insurance status and key markers of pre-ESRD care. Models include state and year fixed effects. The assumption of parallel trends in pre-ACA period is supported using plots of monthly data and the results are robust to using narrower age windows. Among patients age <65 not on Medicare, insurance rates increased from 82.4% pre-ACA to 86.7% in 2014, 89.3% in 2015 and 92.1% in 2016. These patients also experienced increases in pre-ESRD nephrology care, use of home dialysis and use of anemia medication; effects on vascular access were equivocal. Patients in states that expanded Medicaid had 3.4 percentage point greater increases in insurance coverage than those in non-expansion states. They also experienced greater increases in pre-ESRD nephrology care and better vascular access, but no change in the use of home dialysis. Overall, these findings demonstrate that several key indicators of pre-ESRD care improved post-ACA implementation, but which indicators improved differed somewhat across the two affected populations: (A) all adults younger than 65 and not on Medicare and (B) adults younger than 65 in Medicaid expansion states. Our findings are consistent with improved access to care that has significant potential to improve clinical outcomes for those with advanced kidney disease in the United States. The magnitudes of the effects are relatively large. Overall, uninsurance fell dramatically during the post-ACA period. About 25-33% of the patients who gained insurance also gained relevant pre-ESRD care, demonstrating the important role of health insurance coverage in access to pre-ESRD care. These are meaningful changes in the context of a clinically and economically vulnerable population. Further research can establish the extent to which the observed improvements in pre-ESRD care affect post-ESRD outcomes such as mortality, hospitalization and access to kidney transplantation.