Table 6.

Clinical score^a to predict laboratory diagnosis of urinary tract infection using European guidelines.^b

Cut-off point (% at or above cut-off point)	Sensitivity	Specificity	PPV	NPV	Correctly classified %	LR+ve	LR−ve
≥0 (100%)	100	0	–	–	62	1.00	–
≥1 (83%)	92	31	69	71	69	1.34	0.25
≥2 (52%)	65	69	77	54	66	2.07	0.51
≥3 (23%)	31	90	84	44	53	3.15	0.77
≥4 (5%)	7	99	95	39	42	11.52	0.93
>4 (0%)	0	100	–	–	38	–	1.00

^aScore weighted according to rounded logistic coefficients based on sum of urine cloudiness = 1, urine smell = 1, moderately severe dysuria = 1, and moderately severe nocturia = 1.

^b10³ colony-forming units per ml. PPV = positive predictive value. NPV = negative predictive value. LR+ve = likelihood ratio for a positive test. LR–ve = likelihood ratio for a negative test. Predictive value of the clinical score with the four independently predictive variables had an area under the ROC curve of 0.71 (95% CI = 0.67 to 0.76). Including a history of any haematuria (using a different cut-off for haematuria compared with other symptoms) slightly improved sensitivity of the clinical score: a score of two or more out of the five variables (62% of the sample) had sensitivity 75% (191/254) specificity = 61% (94/154), PPV = 76% (191/251), NPV = 60% (94/157) LR+ve = 1.93, and LR-ve = 0.41.