Medicare advantage and dialysis facility choice.

Objective: To compare the characteristics of dialysis facilities used by traditional Medicare (TM) and Medicare advantage (MA) enrollees with end-stage kidney disease (ESKD).

Data Sources: We used 20% TM claims and 100% MA encounter data from 2018 and publicly available data from the Centers for Medicare and Medicaid Services.

Study Design: We compared the characteristics of the dialysis facilities treating TM and MA patients in the same ZIP code, adjusting for patient characteristics. The outcome variables were facility ownership, distance to the facility, and several measures of facility quality.

Data Collection/extraction: We identified point prevalent dialysis patients as of July 15, 2018.

Principal Findings: Compared to TM patients in the same ZIP code, MA patients were 1.84 percentage points more likely to be treated at facilities owned by the largest two dialysis organizations and 1.85 percentage points less likely to be treated at an independently owned facility. MA patients went to further and lower quality facilities than TM patients in the same ZIP code. However, these differences in facility quality were modest. For example, while the mean dialysis facility mortality rate was 21.85, the difference in mortality rates at facilities treating MA and TM patients in the same ZIP code was 0.67 deaths per 100 patient-years. Similarly, MA patients went to facilities that were, on average, 0.15 miles further than TM patients in the same ZIP code.

Conclusion: MA enrollees with ESKD were more likely than TM enrollees in the same ZIP code to use the dialysis facilities owned by the two largest chains, travel further for care, and receive care at lower quality facilities. While the magnitude of differences in facility distance and quality was modest, the direction of these results underscores the importance of monitoring dialysis network adequacy as ESKD MA enrollment continues to grow.