Table 2. Sensitivities and Specificities of Leukocyte Esterase and Nitrite, Alone and in Combination.

	All Patients (n = 199)		Catheterizationa (n = 99)		Clean-catchb (n = 100)
Test Threshold	Se, %	Sp, %	Se, %	Sp, %	Se, %	Sp, %
LE ≥ trace	97	75	90	96	100	52
LE ≥ small	83	85	90	97	79	72
LE ≥ moderate	41	94	30	100	47	86
LE = large	28	98	20	100	32	96
Nitrite	45	99	40	99	47	99
LE ≥ trace and nitrite	45	99	40	99	47	99
LE ≥ trace or nitrite	97	75	90	96	100	52

LE, leukocyte esterase; Se, sensitivity; Sp, specificity

^aSubgroup of patients whose urine was collected by catheterization

^bSubgroup of patients whose urine was collected by a clean-catch method