TABLE 3.

Comparison of PIMA™ analysers versus National Health Laboratory Services as categorised by CD4+ T-cell counts.

Measure of agreement	≤ 350 cells/mm3†	351 cells/mm – 500 cells/mm3‡	≤ 500 cells/mm3§	> 500 cells/mm3¶	All CD4+ T-cell counts††
Median bias	21	13	21	-23	18
BA bias (± 1 s.d.)	32.9 ± 61.0	21.5 ± 90.8	30.1 ± 69.4	-36.1±150.04	17.5 ±93.8
95% CI bias	23.4–42.3	-3.5–46.6	20.8–39.4	-78.3–6.1	6.2–28.8
BA 95% LOA	-89.2 –154.9	-160.0–203.0	-108.7–168.9	-336.2–263.9	-170.0–205.0
% Similarity to predicate (% SIM mean ± s.d.)	107.4 ± 15.2	102.7 ± 10.5	106.2 ± 14.35	97.97 ± 10	106 ± 15.5
%SIM CV	14.20%	10.20%	13.50%	10.20%	14.60%

BA, Bland-Altman; LOA, limits of agreement.

^†n = 164;

^‡n = 53;

^§n = 217;

^¶n = 51;

^††n = 268.