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Abstract: FR-OR15

Mechanism of Higher Incidence of ESKD Among Blacks and Hispanics vs. Whites in the United States

Session Information

Category: CKD (Non-Dialysis)

  • 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

  • Yan, Guofen, University of Virginia, Charlottesville, Virginia, United States
  • Norris, Keith C., University of California Los Angeles David Geffen School of Medicine, Los Angeles, California, 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, Salt Lake City, Utah, United States
  • Cheung, Alfred K., University of Utah, Salt Lake City, Utah, United States
Background

In the U.S., Blacks and Hispanics have higher incidence of ESKD than Whites. Whether this is driven by lower mortality prior to ESKD or inherently faster progression to ESKD has not been clearly determined because most studies used prevalent cohorts that created survival bias. We examined this issue using a newly constructed national cohort of patients with new-onset CKD.

Methods

We identified 834,270 individuals with new-onset CKD in the US Veterans Health Administration (VHA) between 2002 and 2015, followed through 2016. CKD onset was defined as the first occurrence when there were two eGFR values (CKD-EPI equation) <60 mL/min/1.73 m2 that were >90 days apart, not in ESKD. We excluded patients in VHA for <2 years prior to the first eGFR<60. Thus, the time of study entry should be close to the CKD onset for each individual. We examined jointly the cause-specific (CS) hazards ratios for two competing events, occurrence of ESKD and pre-ESKD death.

Results

Upon study entry, 704,557 Whites, 98,082 Blacks, and 31,631 Hispanics had similar mean eGFRs (49-50 ml/min/1.73m2). Ten years after CKD onset, fractions of patients entering ESKD were 1.3-2.5 times greater for Blacks and Hispanics vs. Whites across six age groups (Table). CS hazards for ESKD was 2.1-2.9 times greater for Blacks and 1.2-2.7 times greater for Hispanics vs. Whites. CS hazards for pre-ESKD death were similar for Blacks and only modestly lower for Hispanics vs. Whites across ages.

Conclusion

More Blacks and Hispanics to ESKD were driven by their greater hazards for ESKD due to more rapid decline in kidney function, not through lower mortality prior to ESKD. Delineation and elimination of the causes of faster kidney function declines are therefore the appropriate strategies to improve clinical outcomes in Blacks and Hispanics with CKD, instead of attributing the higher incidence to pre-ESKD survival bias.

Crude CS hazards ratios and 95% confidence intervals (CI) for ESKD and for pre-ESKD death
Age
(years)
10-year cumulative incidence of
ESKD following CKD onset (%)
Black vs White
Cause-specific hazards ratios (95% CI)
Hispanic vs White
Cause-specific hazards ratios (95% CI)
BlackHispanicWhiteESKDpre-ESKD deathESKDpre-ESKD death
18-4545.732.620.92.46 (2.17-2.80)1.15 (0.96-1.38)1.77 (1.37-2.29)1.01 (0.67-1.51)
46-5532.730.913.92.65 (2.51-2.81)0.90 (0.86-0.95)2.57 (2.32-2.85)0.92 (0.82-1.03)
56-6521.020.08.32.90 (2.79-3.01)0.98 (0.95-1.01)2.67 (2.50-2.85)0.86 (0.81-0.90)
66-7510.07.74.32.48 (2.34-2.62)1.04 (1.01-1.06)1.82 (1.65-2.01)0.87 (0.84-0.91)
76-854.23.32.02.39 (2.18-2.62)1.10 (1.07-1.12)1.66 (1.44-1.93)0.94 (0.91-0.97)
86-1001.30.80.62.11 (1.54-2.89)0.97 (0.93-1.00)1.21 (0.66-2.20)0.97 (0.92-1.03)

Funding

  • NIDDK Support