Association Between Nephrologist Ownership of Dialysis Facilities and Clinical Outcomes.

IMPORTANCE: Ownership of US dialysis facilities presents a financial conflict of interest for nephrologists, who may change their clinical practice to improve facility profitability.

OBJECTIVE: To investigate the association between nephrologist ownership of freestanding dialysis facilities and clinical outcomes.

DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study was conducted using US Renal Data System data linked to a data set of freestanding nonpediatric dialysis facility owners. Participants were a sample of all adults with fee-for-service Medicare receiving dialysis for end-stage kidney disease from January 2017 to November 2017 at included facilities. Data were analyzed from April 2020 through August 2022.

EXPOSURES: Outcomes associated with nephrologist ownership were assessed using a difference-in-differences analysis comparing the difference in outcomes between patients treated by nephrologist owners and patients treated by nonowners within facilities owned by nephrologists after accounting for differences in patient outcomes between nephrologist owners and nonowners in other facilities.

MAIN OUTCOMES AND MEASURES: Outcomes plausibly associated with nephrologist ownership were evaluated: (1) treatment volumes (missed treatments and transplant waitlist status); (2) erythropoietin-stimulating agent (ESA) use and related outcomes (anemia, defined as hemoglobin level <10 g/dL, and blood transfusions), (3) quality metrics (mortality, hospitalizations, 30-day readmissions, hemodialysis adequacy, arteriovenous fistula use, and hemodialysis catheter use for ≥3 months), and (4) home dialysis use.

RESULTS: A cohort of 251 651 patients (median [IQR] age, 66 [46-85] years; 112 054 [44.5%] women; 9765 Asian [3.9%], 86 837 Black [34.5%], and 148 617 White [59.1%]; 38 938 Hispanic [15.5%]) receiving dialysis for end-stage kidney disease were included. Patient treatment by nephrologist owners at their owned facilities was associated with a 2.4 percentage point (95% CI, 1.1-3.8 percentage points) higher probability of home dialysis, a 2.2 percentage point (95% CI, 3.6-0.7 percentage points) lower probability of receiving an ESA, and no significant difference in anemia or blood transfusions. Patient treatment by nephrologist owners at their owned facilities was not associated with differences in missed treatments, transplant waitlisting, mortality, hospitalizations, 30-day readmissions, hemodialysis adequacy, or fistula or long-term dialysis catheter use.

CONCLUSIONS AND RELEVANCE: This cross-sectional cohort study found that nephrologist ownership was associated with increased home dialysis use, decreased ESA use, and no change in anemia or blood transfusions.