The Kidney Failure Risk Equation (KFRE), developed in a geriatric cohort, is a widely validated equation to predict kidney failure for adults with mild-to-moderate chronic kidney disease (CKD).1 When applied to the Chronic Kidney Disease in Children (CKiD) cohort, the KFRE yielded good discrimination2 and was recommended for pediatric practice,3 despite heterogeneous CKD etiologies and progression in children. However, this analysis only presented limited assessment of calibration—the other metric, along with discrimination, necessary for instrument validation—and this deserves particular attention in the application of an adult instrument for children.