TABLE 4.

Agreement between shipped-sample CD4 and CD8 counts^a

CD4 stratum and laboratory	n	Predicate CD4 count	Agreement CD4 count			Pb	Predicate CD8 count	Agreement CD8 count			P
			10th	50th	90th			10th	50th	90th
All strata
All labs	411	272	−67	7	79	<0.01	992	−238	−51	100	<0.01
A	84	311	−103	−17	61	<0.01	1,068	−310	−136	7	<0.01
B	74	378	−135	−34	55	<0.01	1,129	−437	−129	35	<0.01
C	79	237	−16	13	73	<0.01	845	−86	11	136
D	86	232	−24	12	70	<0.01	984	−179	−44	64	<0.01
E	88	200	−25	25	181	<0.01	927	−190	3	220
<200
All labs	168	115	−49	2	40		721	−274	−34	104	<0.01
A	33	168	−83	−16	9	<0.01	875	−585	−157	−29	<0.01
B	25	178	−94	−14	35	<0.03	964	−491	−144	108	<0.01
C	36	106	−13	10	42	<0.02	584	−68	19	159
D	36	105	−10	7	48	<0.01	625	−114	−16	61
E	38	103	−24	11	55	<0.01	680	−191	−2	162
200–500
All labs	156	337	−77	17	101	<0.01	1,080	−230	−65	99	<0.01
A	33	380	−115	9	76		1,202	−247	−108	77	<0.01
B	31	396	−169	−46	62	<0.01	1,159	−526	−129	29	<0.01
C	27	318	−28	14	83	<0.01	1,003	−86	1	114
D	33	319	−21	21	83	<0.01	1,066	−201	−93	53	<0.01
E	32	274	−239	68	225	<0.01	1,055	−135	9	852
>500
All labs	87	680	−102	12	144		1,191	−237	−63	108	<0.01
A	18	742	−145	−29	81		1,198	−202	−96	73	<0.01
B	18	752	−182	−49	155		1,297	−373	−119	59	<0.01
C	16	677	−26	47	166	<0.01	1,133	−130	3	142
D	17	622	−49	12	141		1,234	−237	−19	153
E	18	602	−14	74	262	<0.01	1,138	−307	−7	184

^aAgreement was determined by subtracting the absolute count obtained by the predicate method from the absolute count obtained by the TruCount method for the same sample. The estimated 10th, 50th, and 90th percentiles of the differences in absolute counts (cells per microliter) are given. 

^bP value for the estimated 50th percentile by the Wilcoxon signed-rank test.