Table 5.

Model Performance When Used on External Validation Cohort for Different Clinical Scenarios

Model	AUC ROC Validation Cohort (95% CI)	Hosmer-Lemeshow Test P Value*	Brier Score†
Full model, with interaction terms‡	0.88 (0.85–0.91)	0.54	0.132
No PET	0.77 (0.74–0.80)	0.39	0.190
No histology	0.87 (0.85–0.90)	0.38	0.135
No PET, no histology	0.76 (0.73–0.79)	0.68	0.193

Definition of abbreviations: AUC ROC = area under the receiver operating characteristic curve; CI = confidence interval; PET = positron emission tomography

Hosmer-Lemeshow and Brier scores are for calibrated model using the general calibration method (17). For model performance without calibration, see Tables E5 (No PET), E7 (No histology), and E9 (No PET, no histology).

^*Hosmer-Lemeshow test, P < 0.05 indicates poor calibration.

^†Brier scores reflect the mean squared difference between predicted outcomes and the actual outcomes. Brier scores range from 0 to 1, with lower scores being better.

^‡Full model as specified in Table 2.