For children and adolescents with end stage renal disease, a higher estimated glomerular filtration rate (eGFR) at the time of dialysis initiation is associated with an increased risk of death, reports a study in the American Journal of Kidney Diseases.
The study used US Renal Data System data on 9963 patients aged 1 to 17 (median 13 years) starting dialysis between 1995 and 2016. Using the pediatric-specific bedside Schwarz equation, initial eGFR was classified as less than 5 mL/min/1.73 m2 in 19% of patients, between 5 and 7 mL/min/1.73 m2 in 22%, between 7 and 9 mL/min/1.73 m2 in 23%, between 9 and 12 mL/min/1.73 m2 in 20%, and 12 mL/min/1.73 m2 or higher in 17%. Time to death from any cause was compared among eGFR groups, with adjustment for case-mix variables, height, body mass index, and hemoglobin and serum albumin levels.
At a median follow-up of 1.4 years, 696 patients died; the overall mortality rate was 31 per 1000 patient-years. Mortality was incrementally higher for pediatric patients with higher eGFRs: adjusted hazard ratios were 0.57 in the under 5 mL/min/1.73 m2 group versus 1.31 in the 12 mL/min/1.73 m2 and higher group (with eGFR between 7 and 9 mL/min/1.73 m2 as the reference group). The association between eGFR and mortality was consistent among patients aged 6 years or older but was weaker in the relatively small group (1263 patients) under age 6.
The association between eGFR at dialysis initiation and mortality in adults remains controversial, with some studies reporting no benefit of earlier dialysis. Few studies have looked at the relationship between eGFR and mortality in pediatric dialysis patients.
This retrospective study finds increased mortality among children and adolescents with higher eGFR at dialysis initiation. The association appears to be modified by age, with an attenuated effect in children less than 6 years old. The authors emphasize the need for further studies in this younger age group, as well as studies evaluating the benefits of starting dialysis at lower eGFRs in pediatric kidney disease [Okuda Y, et al. Estimated GFR at dialysis initiation and mortality in children and adolescents. Am J Kidney Dis 2019; DOI: 10.1053/j.ajkd.2018.12.038].