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Abstract: FR-OR22

Time-Dependent Risk Differences in Kidney Failure and Death Between Black and White Veterans Following Incident CKD

Session Information

Category: CKD (Non-Dialysis)

  • 2201 CKD (Non-Dialysis): Epidemiology‚ Risk Factors‚ and Prevention

Authors

  • Yan, Guofen, University of Virginia, Charlottesville, Virginia, United States
  • Nee, Robert, Walter Reed National Military Medical Center, Bethesda, Maryland, United States
  • Scialla, Julia J., University of Virginia, Charlottesville, Virginia, United States
  • Yu, Wei, University of Virginia, Charlottesville, Virginia, United States
  • Greene, Tom, University of Utah Health, Salt Lake City, Utah, United States
  • Cheung, Alfred K., University of Utah Health, Salt Lake City, Utah, United States
  • Norris, Keith C., University of California Los Angeles, Los Angeles, California, United States
Background

Recent research indicates that among US veterans with incident CKD defined using the new 2021 CKD-EPI creatinine equation, Black patients had 27-37% higher adjusted rates of kidney failure (KF) than White patients. We examined whether this higher rate persisted in the entire course of CKD or only within a certain time period following incident CKD.

Methods

The study included 180,881 non-Hispanic White and 32,187 non-Hispanic Black veterans, aged 18-90 years, with incident CKD from 2003-2008 in the US Veterans Health Administration, followed through 2018. Incident CKD was defined by the first time when two eGFR values >3 months apart were both <60 mL/min/1.73 m2 using the 2021 CKD-EPI equation. We calculated cause-specific hazard ratios (HR) of KF, censoring on death, and HRs of death (including death after KF) for Blacks versus Whites in five consecutive 2-year intervals for a total of 10 years, adjusting for demographics, clinical factors, and comorbidities.

Results

At incident CKD, Black veterans were on average younger than White veterans (66 and 74 years, respectively) with similar mean eGFR (50-51 mL/min/1.73 m2). Over 10 years of follow-up, the adjusted risk of KF was 30% greater in Blacks than in Whites (Table), but this difference was more pronounced over the early years of CKD onset (e.g., 38% greater risk in years 0-2) than at later years (only 8% greater risk, p>0.05 in years 8-10). Despite the overall similar adjusted mortality risks after adjusting for major confounding of age along with other covariates, the difference evolved over time, with a greater adjusted risk of death for Blacks during the first 4 years of CKD onset, followed by a lower risk thereafter. These risk differences over time were consistent across subgroups such as those with and without specific comorbidities (e.g., hypertension, diabetes, or cardiovascular diseases).

Conclusion

Black individuals are particularly susceptible to adverse outcomes during the first several years of CKD onset, which demands a stronger urgency for close evaluation in the earlier years of CKD to improve outcomes.

Adjusted HRs (95% CIs) for Black versus White veterans in years after incident CKD
OutcomeThe entire 10-year periodYears after CKD onset
0-22-44-66-88-10
Kidney failure1.30 (1.24-1.37)1.38 (1.26-1.52)1.44 (1.31-1.57)1.32 (1.20-1.45)1.23 (1.11-1.36)1.08 (0.96-1.21)
Death1.01 (0.99-1.03)1.27 (1.23-1.32)1.07 (1.03-1.11)0.95 (0.91-0.99)0.94 (0.91-0.98)0.85 (0.82-0.89)

Funding

  • NIDDK Support