Figure 12: Receiver operating characteristic curves (A) and calibration curves (B) for prediction of exacerbations of chronic obstructive pulmonary disease.

Analyses that include lung function use pre-bronchodilator measurements. Higher AUC indicates better discrimination, whereas lower ICI indicates better calibration. For more information, see the appendix (p 6). AUC=area under the receiver operating curve. ICI=integrated calibration index.