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

The vertical axis of Fig 2 depicts the error in prediction of serum calcium concentration (mg/dl) that will be caused if specific input variable is removed from the mathematical model generated by Random Forest. 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 calcium were included in this analysis.