States with broader Medicaid coverage have lower incidences of kidney failure and smaller insurance-related gaps in access to kidney disease care. Those are the findings of a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). The results point to the potential benefits of Medicaid expansion on chronic disease prevention and care.

Chronic disease care is a major source of rising health care expenditures, and access to care for uninsured individuals with a chronic disease has eroded over the last decade. The Affordable Care Act is expanding Medicaid coverage of low-income adults, though not all states are participating in this expansion. Most previous studies of Medicaid coverage have focused on primary care or emergency room services and have not carefully examined Medicaid's effects on chronic disease care.

The care of patients approaching kidney failure, or end-stage renal disease (ESRD), is a useful model to study the potential effects of Medicaid expansion on chronic disease care because ESRD care is costly and the quality of pre-ESRD care is tracked nationally.

Manjula Tamura, MD, MPH (VA Palo Alto Health Care System and Stanford University) and her colleagues sought to determine whether states with broader Medicaid coverage of low-income non-elderly adults had a lower incidence of ESRD and better access to pre-ESRD care. They also looked to see whether broad state Medicaid coverage benefitted uninsured adults in addition to those receiving Medicaid.

Using US data, the researchers identified 408,535 adults aged 20 to 64 years who developed ESRD from 2001 through 2008. Medicaid coverage among low-income nonelderly adults living in different states ranged from 12.2% to 66.0%.

Among the major findings:

  • Broader Medicaid coverage among low-income nonelderly adults was associated with a lower incidence of ESRD: for each additional 10% of the low-income nonelderly population covered by Medicaid, there was a 1.8% decrease in ESRD incidence.
  • Low-income nonelderly adults with ESRD who were on Medicaid had better access to care in states with broader Medicaid coverage: For a 50-year-old white woman, the access gap to being put on the kidney transplant waiting list between Medicaid and private insurance decreased by 7.7 percentage points in high vs low Medicaid coverage states. Similarly, the access gap to transplantation decreased by 4.0 percentage points and the access gap to peritoneal dialysis decreased by 3.8 percentage points.
  • Broader Medicaid coverage was associated with some spillover benefits for uninsured adults with ESRD, but these were small and not consistently observed.

"Our study suggests that Medicaid expansion among low-income nonelderly adults could support efforts to prevent kidney failure and improve access to kidney disease care," said Dr. Tamura.

In an accompanying editorial, Rajnish Mehrotra, MD and Larry Kessler, ScD (University of Washington, Seattle) noted that the researchers' work "highlights the intricate web of health insurance, access to care, and ESRD. Their study is timely as a social experiment is unfolding in this country that will allow us to further examine the association between Medicaid coverage and health care outcomes."