TABLE 1.

Correlation coefficients for interassay comparisons at viral loads of <1,000 copies/ml^a

Assay detection (at <1,000 copies/ml)	Correlation coefficients of discordant results of ≥1,000 copies/ml
	Amplicor	RealTime	TaqMan v1	TaqMan v2
Amplicor		NAb	0.52	0.85
RealTime	NA		0.74	0.82
TaqMan v1	0.45	0.54		0.69
TaqMan v2	0.80	0.78	0.68

^aCorrelation coefficients of the interassay comparisons were calculated using the results with a restriction of at least one viral load assay giving a result of <1,000 copies/ml. The assay restricted to <1,000 copies/ml is shown in the left-hand column, and its comparator assay is indicated in the columns. For example, when TaqMan v1 was restricted to values of <1,000 copies/ml, the matching Amplicor test results had an R value of 0.45. Conversely, when the Amplicor test was restricted to <1,000 copies/ml, the matching TaqMan v1 results had an R value of 0.52.

^bNA, not available.