Table 3

Sensitivity, specificity, positive predictive value and negative predictive value for catheter-associated urinary tract infection at different cut-off values of catheter days

Cut-off values of catheter days	Sensitivity (%)	Specificity (%)	PPV (%)	NPV (%)	Youden’s index	AUC	Metric score
2	100	0	65.41	–	0.00000	0.709	1.00
3	100	5.45	66.67	100	0.05455	0.709	1.05
4	99.04	16.36	69.13	90	0.15402	0.709	1.15
5	90.38	29.09	70.68	61.54	0.19476	0.709	1.19
6	78.85	45.45	73.21	53.19	0.24301	0.709	1.24
7	71.15	54.55	74.75	50	0.25699	0.709	1.26
8	56.73	65.45	75.64	44.44	0.22185	0.709	1.22
9	48.08	81.82	83.33	45.45	0.29895	0.709	1.30
10	46.15	83.64	84.21	45.1	0.29790	0.709	1.30
11	41.35	89.09	87.76	44.55	0.30437	0.709	1.30
12	39.42	89.09	87.23	43.75	0.28514	0.709	1.29
14	28.85	94.55	90.91	41.27	0.23392	0.709	1.23
15	27.88	98.18	96.67	41.86	0.26066	0.709	1.26
16	22.12	98.18	95.83	40	0.20297	0.709	1.20
17	16.35	98.18	94.44	38.3	0.14528	0.709	1.15
18	12.5	98.18	92.86	37.24	0.10682	0.709	1.11
20	4.81	100	100	35.71	0.04808	0.709	1.05
21	3.85	100	100	35.48	0.03846	0.709	1.04
22	0.96	100	100		0.00962	0.709	1.01

AUC, area under the curve; NPV, negative predictive value; PPV, positive predictive value.