Dialysis Outcomes Tied to Nephrologist Facility Quality, Widening Racial Inequities

Many patients begin dialysis at the primary facilities of their predialysis nephrologists, even when those facilities are of low quality, a new cohort study of more than 140,000 Medicare beneficiaries found.¹ Initiating dialysis is a risky time; patients receiving dialysis for end-stage kidney disease have a 20% 1-year mortality rate and are hospitalized 1.5 times per year.² The findings, published in JAMA Health Forum, highlighted significant quality concerns and racial disparities in dialysis care access.¹

A new study highlights quality concerns and racial disparities in dialysis care access.

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The researchers used Medicare administrative data of patients initiating dialysis at freestanding US dialysis facilities from January 1, 2015, to October 31, 2020, with 1 year of follow-up. Analyses concluded January 26, 2025. Participants were adults with fee-for-service (FFS) Medicare initiating dialysis.

Continuity of Care vs Quality of Care

The study, which analyzed data from 2015 to 2020, focused on the relationship between dialysis start location and the quality of care at the nephrologist’s primary facility, defined as the location where the nephrologist sees the most patients. Researchers used the 5-star facility rating system published by CMS through Dialysis Facility Compare (DFC) to assess quality and linked these ratings to patient outcomes using percentage points.

The study found that patients were less likely to start dialysis at their nephrologist’s primary facility for each 1-star increase in the facility’s quality rating (0.5; 95% CI, 0.1-0.8; P = .03), suggesting that higher-quality facilities were paradoxically associated with lower rates of primary facility use. In contrast, patients were more likely to start dialysis at their nephrologist’s primary facility when it was geographically close (33.9; 95% CI, 33.0-34.9; P < .001), indicating that proximity may outweigh quality in facility selection. Each additional quality star in a nephrologist’s primary facility was associated with 7.4 percentage points more dialysis starts at 4-star or 5-star facilities (95% CI, 6.9-7.9). Higher-quality facilities were also linked to better outcomes, with 4.5 fewer hospitalizations per 100 person-years for each additional star in the facility’s rating (95% CI, 2.8-6.1).

Disparities in Dialysis Quality Access

Black patients were less likely than White patients to be treated by nephrologists affiliated with high-quality facilities (37.3% vs 45.2%) and were also less likely to start dialysis in high-quality facilities (36.0% vs 46.2%). These disparities remained significant even after adjusting for geographic and demographic factors.

Within the same hospital service area, Black patients were less likely than White patients to start dialysis in a high-quality (4 or 5 stars) facility (2.8 percentage points; 95% CI, 1.7-3.9) and less likely to be seen by a nephrologist whose primary facility was high quality (2.0 percentage points; 95% CI, 1.0-3.0). These gaps persisted even though the study did not find significant differences among other racial or ethnic groups or among patients with dual Medicare-Medicaid eligibility.

In an unadjusted analysis, the researchers found patients were significantly more likely to start dialysis at nephrologists’ primary facilities when those facilities were nearby, regardless of quality.

"A facility’s market share from the previous year was the proportion of patient-months in the regional network provided by that facility," the researchers wrote. "When modeling primary facility starts, we adjusted for the primary facility’s market share. When examining high-quality and close facility starts, we adjusted for the market share of all high-quality and all close facilities in the regional network, respectively. We used the previous year’s market share to avoid simultaneity bias from dialysis starts impacting market share."

When close, primary facility starts exceeded market share by 38 percentage points. If the nearby primary facility was high-quality, high-quality starts were 18 points above market share; if low-quality, high-quality starts were 12 points below. When primary facilities were distant, starts barely exceeded market share (by less than 6 points).

Policy Implications for Kidney Disease

The study found that primary facility starts may worsen racial disparities in dialysis quality, as Black patients had less access to nephrologists whose primary facilities were high quality. The authors suggested that supply-side policy interventions—such as subsidies or incentives to relocate high-quality dialysis facilities—may be needed to improve access and address these inequities.

"In this cohort study of FFS Medicare patients who initiated dialysis for ESKD [end-stage kidney disease], primary facility starts were common, especially if primary facilities were close to patients and even when they were low quality," they wrote. "Given that starts did not correlate with 5-star ratings, policymakers may wish to bolster the DFC’s effectiveness, including improved publicity to patients."

References

1. Lin E, Lung KI, Rapista D, et al. Care continuity, nephrologists’ dialysis facility preferences, and outcomes. JAMA Health Forum. 2025;6(4):e250423. doi:10.1001/jamahealthforum.2025.0423

2. Chronic kidney disease in the United States, 2023. CDC. May 15, 2024. Accessed May 30, 2025. https://www.cdc.gov/kidney-disease/php/data-research/index.html