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 (ESRD) and are less likely to receive a kidney transplant. It is unclear whether AA children experience renal replacement therapy (RRT) for ESRD sooner than non-AA children after accounting for socioeconomic status (SES). Methods Among children with non-glomerular CKD in the Chronic Kidney Disease in Children (CKiD) 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 (IPWs). 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 non-significant (−1.6 years; 95%CI: −4.6, +1.5) and its directionality was consistent with faster GFR decline among AA children (−6.2% vs. −4.4% per year, p= 0.098). 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 GFR 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.

Health‐related quality of life changes following renal transplantation in children

“…24 Such findings underscore the importance of the nephrology community continuing to address issues of equity in transplant access. [25][26][27] This study has a number of important limitations. This research relied on self-report.…”

“…In this sense, kidney transplant may function to eliminate some of the disparities in HRQoL noted among children with ESRD by decreasing the complexity of medical care required for the recipient and the burden of travel to the medical center . Such findings underscore the importance of the nephrology community continuing to address issues of equity in transplant access …”

<p>Nonparametric Assessment of Differences Between Competing Risk Hazard Ratios: Application to Racial Differences in Pediatric Chronic Kidney Disease Progression</p>

“…Since lower socioeconomic status (SES) is associated with AA race, adjustment for SES factors was critical and demonstrated the inclusion of weighting methods for adjusted nonparametric descriptions of the cumulative incidences, as well as for our diagnostic tool. As previously described, 28 inverse probability of exposure weights (IPWs; scaled to the marginal proportion within each group) were constructed based on annual household income (categorized as <$30,000, $30,000 to $75,000, and >$75,000), abnormal birth history (defined as low birth weight, small for gestational age, or premature birth), food assistance in the past year, household having any public insurance, maternal education less than college, participant visiting a private doctor in the past year and male sex.…”

“…We propose and describe nonparametric estimates of the ratio of sHR to csHR, corresponding 95% confidence intervals, and present an applied non-causal example that updates a description of racial differences in time to competing renal replacement therapy events in a pediatric population with chronic kidney disease (CKD). 28 In the analysis presented here, we provide a comprehensive characterization and comparison of sHRs and csHRs for first dialysis and first transplant and demonstrate that this can be accomplished nonparametrically, with adjustment for multiple variables using inverse probability of exposure weights. We further demonstrate how our method leads to the calculation of an alternative estimate of the sHR, the product of the semiparametric csHR estimates and the nonparametric sHR/csHR ratio estimates, which does not violate any tethering constraints nor assume proportionality.…”

Observational Research Using Propensity Scores

“…Various PS matching and weighting applications can be found in studies evaluating the safety 22 and effectiveness 23 of medications in kidney disease patients, evaluating the strength of risk factors in predicting kidney replacement therapy, 24 estimating the protective effect of medications against renal events, 25 estimating the long-term effects of acute kidney injury, 26 and many others. STRENGTHS PS-based methods are useful in settings where outcomes are uncommon because covariates (used to mathematically model treatment as the dependent variable) tend to be more prevalent, especially in observational settings with large numbers of covariates available in electronic medical records or administrative claims databases.…”