Fig. 3.

External validation: a discrimination and b calibration. The predicted probability of pneumonia is calculated by the sum of the predictive values of every independent variable multiplied by presence of every variable. The observed probability of pneumonia is the percentage of patients treated for pneumonia at the ward at any given point on the x-axis. Sens sensitivity, Spec specificity, PPV positive predictive value, NPV negative predictive value, T temperature, L leukocytes, P pulmonary radiography