Racial differences in renal replacement therapy initiation among children with a nonglomerular cause of chronic kidney disease

Abstract

Purpose: African American (AA) adults with chronic kidney disease (CKD) have a faster progression to end-stage renal disease and are less likely to receive a kidney transplant. It is unclear whether AA children experience renal replacement therapy (RRT) for end-stage renal disease sooner than non-AA children after accounting for socioeconomic status (SES).

Methods: Among children with nonglomerular CKD in the Chronic Kidney Disease in Children study, we investigated time to RRT (i.e., first dialysis or transplant) after CKD onset using parametric survival models and accounted for SES differences by inverse probability weights.

Results: Of 110 AA and 493 non-AA children (median age = 10 years), AA children had shorter time to first RRT: median time was 3.2 years earlier than non-AA children (95% CI: -6.1, -0.3). When accounting for SES, this difference was diminished and nonsignificant (-1.6 years; 95% CI: -4.6, +1.5), and its directionality was consistent with faster glomerular filtration rate decline among AA children (-6.2% vs. -4.4% per year, P = .098). When RRT was deconstructed into dialysis or transplant, the time to dialysis was 37.5% shorter for AA children and 53.7% longer for transplant. These inferences were confirmed by the frequency and timing of transplant after initiating dialysis.

Conclusions: Racial differences in time to RRT were almost fully accounted for by SES, and the remaining difference was congruent with a faster glomerular filtration rate decline among AA children. Access to transplant occurred later, yet times to dialysis were shorter among AA children even when accounting for SES which may be due to a lack of organ availability.

Keywords: Chronic kidney disease; Health disparities; Inverse probability weights; Pediatric nephrology; Renal replacement therapy.

Conflict of interest statement

Statement of competing financial interests. All the authors declared no competing interests.

Copyright © 2016 Elsevier Inc. All rights reserved.

Figures

Figure 1

Figure 1A. Unadjusted non-parametric survival step functions of incidence of first renal replacement therapy (RRT), by race. Figure 1B. Weighted by inverse probability weights non-parametric survival step functions of incidence of first RRT adjusted for socioeconomic status (SES) factors listed in Table 2. Dashed lines are based on Weibull distributions for each group with location (β) and scale (σ) and denoted as WE(β,σ).

Figure 2

Figure 2A. Unadjusted non-parametric survival step functions of incidence of first occurrence of dialysis or transplant as competing events, by race. Figure 2B. Weighted by inverse probability weights non-parametric survival step functions of incidence of first occurrence of dialysis or transplant as competing events, by race, adjusted for socioeconomic status (SES). Dashed lines are based on a mixture of Weibull distributions for each group with location (β) and scale (σ) and denoted as WE(β,σ) with corresponding estimated proportions experiencing each competing event.

Figure 3

Frequency and timing of kidney transplant after first dialysis, by race. Line segments around proportions receiving transplant are 95% exact confidence intervals. Percentile boxplots depict the distributions of times to transplant after first dialysis.