Fig. 1

Boxplots of the bias of the different equations in the development sample using 10-fold cross-validation (A) and in the temporary validation sample (B). MDRD-4 and MDRD-6 = Modification of Diet in Renal Disease with 4 and 6 variables; MCQ = Mayo Clinic Quadratic; CKD-EPI = Chronic Kidney Disease Epidemiology Collaboration 2009 and 2021; EKFC = European Kidney Function Consortium; L6 = linear model using 6 predictive variables; G6 = generalized linear model using 6 predictive variables; Q6 = quasi-likelihood model using 6 predictive variables; AE = Argentinian Equation.