TABLE 1.

Between-assay correlations in absolute pneumococcal antibody levels^a

Laboratory comparison and serotype	r	Slope (95% CIb)	Intercept	Biasc	% bias	nd
A vs C
1	0.9599	0.979 (0.913 to 1.046)	−0.057	−0.176	−3.1	71
3	0.8725	0.833 (0.733 to 0.933)	−0.348	−1.057	−28.5	74
4	0.9729	0.868 (0.823 to 0.913)	−0.213	−0.429	−30.2	82
6B	0.9442	1.433 (1.315 to 1.552)	−2.93	2.34	17.6	66
7F	0.9659	1.076 (1.016 to 1.136)	−0.664	−0.262	−5.0	89
8	0.9025	1.242 (1.120 to 1.365)	0.037	1.284	22.2	80
9N	0.9608	1.099 (1.027 to 1.171)	−0.607	−0.044	−0.8	74
9V	0.9484	1.19 (1.107 to 1.274)	−1.176	−0.277	−6.0	84
12F	0.9404	1.167 (1.055 to 1.278)	−1.165	0.143	1.8	54
14	0.9565	1.184 (1.104 to 1.263)	−1.214	0.258	3.2	78
18C	0.9652	1.203 (1.125 to 1.280)	−0.604	−0.062	−2.3	68
19F	0.3473	8.933 (7.092 to 10.774)	−42.688	2.066	31.0	84
23F	0.9605	1.294 (1.210 to 1.378)	−0.548	0.345	−10.8	75
A vs B
1	0.6634	0.666 (0.534 to 0.798)	1.661	−0.002	0.0	82
3	0.7889	0.521 (0.435 to 0.608)	−0.097	−1.814	−67.7	74
4	0.7399	0.679 (0.564 to 0.795)	0.2	−0.246	−19.4	82
6B	0.7852	0.651 (0.536 to 0.766)	1.07	−1.783	−24.5	63
7F	0.6731	0.468 (0.375 to 0.561)	0.612	−2.088	−51.8	90
8	0.675	0.889 (0.726 to 1.052)	0.841	0.385	9.0	82
9N	0.5103	0.314 (0.212 to 0.416)	1.368	−1.706	−47.0	76
9V	0.6744	1.117 (0.922 to 1.312)	−0.961	−0.458	−11.3	84
12F	0.8121	0.255 (0.215 to 0.294)	1.074	−1.728	−59.7	82
14	0.6983	0.685 (0.557 to 0.813)	−0.442	−2.846	−45.8	80
18C	0.6609	3.925 (3.232 to 4.619)	−2.437	4.749	98.3	74
19F	0.2223	5.84 (4.584 to 7.096)	−22.998	2.275	35.8	84
23F	0.7496	0.939 (0.776 to 1.102)	0.07	−0.052	−2.6	69
B vs C
1	0.582	0.404 (0.296 to 0.513)	3.124	−0.698	−11.5	75
3	0.7661	0.548 (0.455 to 0.641)	0.332	−0.916	−39.8	78
4	0.8504	1.024 (0.899 to 1.148)	0.249	0.27	26.6	82
6B	0.7465	0.354 (0.283 to 0.425)	2.467	−3.663	−47.9	70
7F	0.6902	0.304 (0.241 to 0.366)	1.448	−2.676	−58.4	89
8	0.4425	0.296 (0.185 to 0.407)	2.947	−1.668	−29.1	76
9N	0.5121	0.305 (0.207 to 0.404)	1.459	−1.466	−42.1	77
9V	0.7287	0.522 (0.429 to 0.615)	1.584	−1.025	−20.7	86
12F	0.8043	0.188 (0.149 to 0.228)	1.667	−3.24	−73.2	51
14	0.8061	0.422 (0.359 to 0.484)	1.197	−6.302	−64.2	86
18C	0.6582	0.686 (0.548 to 0.823)	4.825	2.362	26.2	80
19F	0.7766	1.738 (1.495 to 1.981)	0.267	3.767	56.9	85
23F	0.9102	0.772 (0.693 to 0.850)	0.225	−0.203	−11.4	73

^aAll possible pairwise comparisons of the three assays are shown for each serotype. Regression statistics were calculated by Deming analysis.

^bCI, confidence interval.

^cAverage bias is presented as the absolute bias and the percent bias for each comparison.

^dNumber of samples which fell within the quantifiable range of the assays in question for a given pairwise comparison.