Fig 3.

Calibration of kidney failure risk equation versus four variable super learner for two and five year prediction of kidney failure. Kidney failure risk equation indicates the four variable KFRE (original equation)¹²; the four variable super learner was trained in Alberta, Canada. The models were tested on the full set of external data, Denmark (A) and Scotland (B). Prediction time horizons: two years for stage G4 chronic kidney disease (top) and five years for the whole cohort (bottom). Risk predictions are grouped into 10 equally large groups (the values below the x axis show the thresholds). Within each group, the observed frequency corresponds to the estimated actual risk (yellow bars). AUC=area under curve; CI=confidence interval; IPA=index of prediction accuracy; KPRE=kidney failure risk equation