Prediction error for Serum PTH concentration by each one of the variables included in the analysis.

The vertical axis of Fig 3 depicts the error in prediction of serum PTH concentration (pg/ml) that will be caused if specific input variable is removed from the mathematical model generated by Random Forest. Paricalcitol, Calcitriol and Calcimimetics are positively associated with PTH because this therapy is given to patients with hyperparathyroidism. The magnitude of prediction error obtained with each variable is being compared with the rest of the variables. Only variables that show a significant effect in predicting values of PTH were included in this analysis.