Table 2.

Discrimination and Calibration for Sequential Five-year Atrial Fibrillation Risk Prediction Models

Model		Discrimination		Calibration
		C-statistic (95% CI)	P Value	GND X2value	P Value
1	CHARGE-AF Simple*	0.795 (0.764–0.827)	-	6.2	0.28
2	CHARGE-AF Enriched†	0.804 (0.771–0.837)	<0.001	2.4	0.80
3	+ Biomarkers‡	0.804 (0.771–0.837)	0.71	2.4	0.79
4	+ MRI§	0.803 (0.770–0.837)	0.13	4.2	0.53
5	+ ECG∥	0.805 (0.773–0.837)	0.86	4.0	0.55
6	+ Subclinical CVD#	0.805 (0.772–0.837)	0.82	3.2	0.67
7	All Predictors**	0.806 (0.774–0.839)	0.81	4.3	0.51
8	Novel MESA††	0.802 (0.769–0.835)	0.93	3.9	0.57

Higher values for C-statistic indicate better models. Discrimination P values are for a likelihood ratio test comparing each model with Model 2, except for 1) Model 2, which is compared with Model 1; and 2) Model 8, which is compared with Model 7. Calibration P values >0.05 indicate adequate fit.

^*Model 1: age, white race, height, weight, systolic BP, diastolic BP, current smoking, antihypertensive medication use, diabetes

^†Model 2: Model 1 + ln(NT-proBNP)

^‡Model 3: Model 2 + serum creatinine, cardiac troponin-T

^§Model 4: Model 2 + end-systolic basal superior lateral wall thickness, end-systolic mid-ventricular anterior wall thickness

^∥Model 5: Model 2 + heart rate, heart rate variability, R amplitude in lead V4, STJ amplitude in lead V5, QRS axis

^#Model 6: Model 2 + ln(CAC + 1), ankle-brachial index, common cIMT, internal cIMT

^**Model 7: all candidate variables

^††Model 8: age, weight, current smoking, ln(NT-proBNP), ln(CAC+1), and cardiac troponin-T

Abbreviations: BP = blood pressure; CAC = coronary artery calcium; CI = confidence interval; cIMT = carotid intima-media thickness; CVD = cardiovascular disease; ECG = electrocardiography; GND = Greenwood-Nam-D’Agostino; LRT = likelihood ratio test; MRI = magnetic resonance imaging; NT-proBNP = N-terminal pro-B-type natriuretic peptide