Table 3.

Predictive value of the nomogram and the a-FRS

Models	AUC	95% CI	P*	Sensitivity	Specificity	PPV	NPV	Accuracy
Nomogram	0.87	0.81–0.94	< 0.001	81.25%	76.00%	46.43%	94.06%	77.07%
a-FRS	0.62	0.52–0.73		65.63%	51.20%	25.61%	85.33%	54.14%

PPV negative predictive value, NPV positive predictive value, a-FRS alternative fistula risk score. *the AUC of nomogram vs the AUC of a-FRS