Variation in estimated glomerular filtration rate at dialysis initiation in children.

Background: Data guiding the timing of dialysis initiation in children are limited. We sought to determine current practice and secular trends in Canada with respect to the timing of dialysis initiation in children based on estimated glomerular filtration rate (eGFR).

Methods: This observational study included incident chronic dialysis patients aged ≤21 years identified from the Canadian Organ Replacement Register who started dialysis in Canada between January 2001 and December 2010 at any of the nine participating Canadian centers (n = 583). Youth were categorized utilizing CKiD Schwartz eGFR into ≥10.5 (higher) or <10.5 ml/min/1.73 m (lower) eGFR groups. Differences at dialysis initiation by facility and region were examined, and secular trends were determined.

Results: Median eGFR at dialysis initiation was 8.1 (interquartile range 5.4-11.0) ml/min/1.73 m. Overall, 29 % of the patients started dialysis with an eGFR of ≥10.5 ml/min/1.73 m. The proportion of children starting with higher eGFR increased from 27.3 % in 2001 to 35.4 % in 2010 (p = 0.04) and differed by treatment facility (12-70 %; p = 0.0001). Factors associated with higher eGFR at dialysis initiation in the adjusted regression model were female sex [odds ratio (OR) 1.48; 95 % confidence interval (CI) 1.02-2.14], genetic cause of end-stage kidney disease (OR 2.77; 95 % CI 1.37-5.58) and living ≥50 km from treatment facility (OR 1.47; 95 % CI 1.01-2.14).

Conclusions: One-third of the children were found to have initiated dialysis with an eGFR ≥10.5 ml/min/1.73 m, however significant practice variation exists with respect to timing of dialysis initiation by treatment facility. More data is required to evaluate the clinical implications of this practice variation.