Performance evaluation of the Pima™ point-of-care CD4 analyser using capillary blood sampling in field tests in South Africa

Table 3 Primary health care clinic field testing using capillary blood

PHASE III	Rural clinic Pima™ (3 sites) versus Predicate (Phase IIIA)		Inner-city clinic Pima™ (1 site) versus Predicate (Phase IIIB)
	PREDICATE	Pima™	PREDICATE	Pima™ *Lancet 1* *(Sarsedt)*	PREDICATE	Pima™ *Lancet 2* *(Caralet Blue)*
N	96	96	87	87	52	52
Range of CD4 counts*	2 - 1871	31 - 2747	2 - 1604	1 - 1358	3 - 966	2 - 968
Mean CD4 count*(median)	617.5 (492.0)	719.4 (677.5)	350 (302.0)	359.0 (305.0)	268.4 (255.5)	257.2 (238.0)
% Similarity to Predicate ( *%SIM* Mean ± SD)	114.8% ± 32.6		101.4% ± 10.1		98.6% ± 11.2
%SIM CV ^#	28.4%CV		10.0%		11.3%
BA bias* ± 1 STDev (PIMA - PLG) (95% CI of bias mean)	+105.7 ± 225.4 (60.1 to 151.4)		+8.9 ± 112.3 (-14.9 to 32.8)		-11.2 ± 69.3 (-30.5 to 8.1)
BA 95% LOA*	-336.0 to 547.0		-211.1 to 229.0		-147.0 to 124.6

Statistical analysis of for Pima™ analysers field-tested in Phases IIIA and IIIB across two rural (N = 96) and one inner-city HCT clinic (N = 139), respectively, versus predicate reporting. All values, with the exception of N, refer to CD4 cell counts in cells/mm³. BA = Bland Altman statistical analysis. LOA = limits of agreement. #Precision of Pima™ to Predicate method expressed as %SIM CV.
*cells/mm³