4.

Efficacy of No. 4 lymph node compared with tumor size and T stage in predicting No. 5, 6 lymph node metastasis

Variables	No. 4 (+)			Tumor size			T stage
	%	95% CI		%	95% CI		%	95% CI
PPV, positive predictive value; NPV, negative predictive value; 95% CI, 95% confidence interval.
Sensitivity	81.25	75.32−87.33		70.00	62.36−77.98		83.75	77.52−89.36
Specificity	85.44	79.66−91.23		36.36	24.57−48.31		21.89	6.58−37.14
Accuracy	89.70	83.51−95.47		43.07	33.15−53.65		58.06	45.22−71.56
PPV	75.58	68.22−82.21		56.81	46.57−66.33		19.14	14.71−34.66
NPV	94.73	89.41−99.38		87.69	80.46−94.33		5.78	0.33−16.39