Incidence of Initial Renal Replacement Therapy Over the Course of Kidney Disease in Children

Abstract

The Chronic Kidney Disease in Children Study, a prospective cohort study with data collected from 2003 to 2018, provided the first opportunity to characterize the incidence of renal replacement therapy (RRT) initiation over the life course of pediatric kidney diseases. In the current analysis, parametric generalized gamma models were fitted and extrapolated for RRT overall and by specific treatment modality (dialysis or preemptive kidney transplant). Children were stratified by type of diagnosis: nonglomerular (mostly congenital; n = 650), glomerular-hemolytic uremic syndrome (HUS; n = 49), or glomerular-non-HUS (heterogeneous childhood onset; n = 216). Estimated durations of time to RRT after disease onset for 99% of the nonglomerular and glomerular-non-HUS groups were 42.5 years (95% confidence interval (CI): 31.0, 54.1) and 25.4 years (95% CI: 14.9, 36.0), respectively. Since onset for the great majority of children in the nonglomerular group was congenital, disease duration equated with age. A simulation-based estimate of age at RRT for 99% of the glomerular population was 37.9 years (95% CI: 33.6, 63.2). These models performed well in cross-validation. Children with glomerular disease received dialysis earlier and were less likely to have a preemptive kidney transplant, while the timing and proportions of dialysis and transplantation were similar for the nonglomerular group. These diagnosis-specific estimates provide insight into patient-centered prognostic information and can assist in RRT planning efforts for children with moderate-to-severe kidney disease who are receiving regular specialty care.

Keywords: dialysis; kidney disease; kidney transplantation; pediatrics; prospective studies; renal insufficiency; renal replacement therapy.

Figure 1

Incidence of renal replacement therapy (RRT) after kidney disease onset among participants with nonglomerular (blue; n = 650), glomerular–hemolytic uremic syndrome (HUS) (green; n = 49), and glomerular–non-HUS (red; n = 216) diagnoses, Chronic Kidney Disease in Children Study, 2003–2018. Continuous step functions represent nonparametric estimates of the cumulative incidence of RRT. Dashed lines represent group-specific parametric survival models based on the generalized gamma (GG) family, with parameters listed as GG(β, σ, κ) in the figure key. 99th percentile times to RRT (in years) after kidney disease onset are presented for patients with glomerular–non-HUS (red dot; 25.4 years, 95% confidence interval: 14.9, 36.0) and nonglomerular (blue dot; 42.5 years, 95% confidence interval: 31.0, 54.1) disease.

Figure 2

Characterization of age at renal replacement therapy (RRT) among patients with glomerular (non–hemolytic uremic syndrome) chronic kidney disease, by age at disease onset (x-axis) and years from onset to RRT (y-axis), Chronic Kidney Disease in Children Study, 2003–2018. The graph shows observed (gray) and imputed (black) data from a single imputation. Solid points denote observed study participants, and open points denote unseen fast progressors. The data and model were based on those presented in Figure 1. Dashed reference lines are provided for different ages at RRT.