TABLE 3.

Z-tests for comparison of two sets of statistical data

Age group and marker	Sensitivity				Specificity				PPV				NPVa
	2001	2002	z-test	P	2001	2002	z-test	P	2001	2002	z-test	P	2001	2002	z-test	P
All ages
Pleocytosis	0.86	0.89	−0.669	0.5031	0.66	0.56	2.138	0.0325
Protein elevated	0.39	0.43	−1.024	0.3058	0.61	0.55	1.351	0.1767
Pleocytosis and protein	0.36	0.43	−1.703	0.0886	0.79	0.70	1.516	0.129
Pleocytosis and/or protein	0.88	0.89	−0.13	0.8966	0.48	0.41	2.209	0.027
0 to ≤2 mo	0.65	0.79	−1.49	0.137	0.80	0.57	2.443	0.0145	0.85	0.66	2.01	0.044	0.57	0.72	−1.593	0.111
>2 mo to ≤18 yr	0.97	1.0	−0.452	0.651	0.71	0.61	1.506	0.131	0.76	0.36	6.026	<0.001	0.96	1.0	−0.602	0.547
>18 yr	1.0	1.0			0.46	0.50	−0.44	0.66	0.41	0.05	3.96	<0.001	1.0	1.0	0

^aNPV, negative predictive value.