TABLE 3.

Analysis of median antibody titers calculated from the VDRL and FTA-ABS IgM test results of reference laboratories in comparison to the median titers calculated from the results of all participating laboratories

Assay	Date (mo/yr)	Reference laboratory result			Participant result
		Sample no.	Median titer	Range	No. of results	Median titer	Range	Acceptable range	Correct (%)	Total (%)
VDRL	3/2000	2000/21	16	8-32	197	16	1-128	4-64	98.0	63.6
		2000/22	0	0-1	181	0	0-16	0-0.9	70.7
	11/2000	2000/41	8	4-8	158	8	1-64	2-32	98.8	64.8
		2000/42	0	0-1	143	0	0-2	0-0.9	72.1
	3/2001	2001/21	0	0	173	0	0-4	0-0.9	79.2	70.8
		2001/22	32	16-64	188	16	0-128	8-128	96.3
	9/2001	2001/41	0	0-1	151	0	0-32	0-1	88.1	76.8
		2001/42	0	0	148	0	0-4	0-0.9	83.1
	3/2002	2002/21	128	64-512	207	128	0-1,024	32-512	94.2	73.9
		2002/22	0	0	192	0	0-4	0-0.9	84.4
	9/2002	2002/51	0	0	168	0	0-<2	0-0.9	92.2	78.6
		2002/52	0	0-1	168	0	0-64	0-1	82.8
	3/2003	2003/21	16	8-16	201	16	0-256	4-64	96.0	81.6
		2003/22	0	0	199	0	0-16	0-0.9	85.9
	9/2003	2003/51	4	0-4	161	2	0-32	1-16	76.4	59.0
		2003/52	0	0	161	0	0-<2	0-0.9	82.6
FTA-ABS IgM	3/2000	2000/21	80	40-640	65	40	0-5,120	20-320	64.6	50.0
		2000/22	0	0	64	0	0-12	<5	78.1
	11/2000	2000/41	80	80-160	50	10	0-640	20-320	66.0	59.1
		2000/42	0	0	50	0	0-10	<5	84.0
	3/2001	2001/21	0	0	62	0	0-16	<5	82.2	43.0
		2001/22	160	40-160	61	160	0-1,280	40-640	52.4
	9/2001	2001/41	0	0	48	0	0-160	<5	85.4	85.4
		2001/42	0	0	47	0	0-5	<5	93.6
	3/2002	2002/21	160	40-320	61	40	0-2,560	40-640	72.1	59.4
		2002/22	0	0	60	0	0-12	<5	88.4
	9/2002	2002/51	0	0	47	0	<5	<5	100.0	100.0
		2002/52	0	0	47	0	<5	<5	100.0
	3/2003	2003/21	20	0-80	55	80	0-320	5-80	56.4	52.7
		2003/22	0	0	55	0	0-12	<5	96.4
	9/2003	2003/51	80	10-256	43	80	0-2,560	20-320	69.8	69.8
		2003/52	0	0	43	0	<5	<5	100.0