Table I.

Inter-laboratory correlation for pneumococcal antibody measurements.

	r (Spearman’s Correlation)
	A vs B	A vs C	B vs C
1	0.33	0.61	0.60
3	0.39	0.89	0.42
4	0.83	0.74	0.79
5	0.56	0.78	0.60
6B	0.53	0.90	0.63
7F	0.31	0.40	0.06
8	0.62	0.93	0.67
9N	0.48	0.92	0.31
9V	0.42	0.90	0.62
12F*	−0.03	-	-
14	0.36	0.48	0.28
18C	0.88	0.68	0.67
19A	0.19	0.24	0.64
19F	0.47	0.61	0.89
2	0.41	0.43	0.86
10A	0.28	0.36	0.38
11A	0.35	0.55	0.71
15B	0.28	0.80	0.21
17F	0.67	0.74	0.81
20	0.43	−0.27	−0.48
22F	0.55	0.68	0.10
23F	0.19	0.89	0.16
33F	−0.21	0.51	−0.18

The nine bottom rows contain serotypes unique to the 23-serotype assay which were not included in the 14-serotype assay.

^*Statistical analysis could not be performed for comparisons involving Laboratory C for serotype 12F, as all 10 results for that laboratory and serotype fell below the lower limit of detection, which did not permit rank order determination.