TABLE 2.

Comparison of the Abbott RealTime HCV and HIV-1 viral load assays with comparator assays

Abbott RealTime assay	Assay used versus Abbott RealTime assay	No. of samples	r2a	Mean differenceb	Regression (y = ax + b)a		% of samples with difference
					a	b	Comparator < Abbottc	Abbott < comparatord
HCV	LcX	92	0.89	−0.35	0.95	0.54	2.2	3.2
	COBAS Amplicor	146	0.81	−0.08	0.75	1.41	2.7	2.0
	COBAS TaqMan	161	0.83	−0.25	0.84	1.02	4.3	4.3
	bDNA	36	0.98	0.06	0.93	0.12	0	0
HIV	LcX	128	0.82	−0.11	1.00	0.14	3.1	1.6
	COBAS Amplicor	115	0.84	−0.14	0.87	0.61	0.9	0.9
	COBAS TaqMan	55	0.76	−0.24	0.93	0.62	1.8	1.8
	bDNA	168	0.90	−0.14	0.93	0.38	0	1.8

^aSpearman regression coefficient and equation of regression analysis.

^bThe mean difference was calculated as follows: mean log₁₀ Abbott RealTime assay − mean log₁₀ comparator results.

^cPercentage of samples with a mean difference 1 log₁₀ higher in the Abbott RealTime assay than in the comparator assay.

^dPercentage of samples with a mean difference 1 log₁₀ higher in the comparator assay than in the Abbott RealTime assay.