TABLE 3.

Systematic bias at medical decision point by site

Virus	Site	Medical decision pointa	Medical decision pointb	No. of pairs within linear range	Predicted value at medical decision pointb,c	Biasb	95% CI of biasb
HBV	1	2,000	3.30	147	3.31	0.009	(−0.010 to 0.027)
		20,000	4.30	147	4.31	0.010	(−0.005 to 0.024)
	2	2,000	3.30	147	3.34	0.038	(0.023 to 0.052)
		20,000	4.30	147	4.34	0.036	(0.024 to 0.047)
	3	2,000	3.30	147	3.32	0.015	(0.001 to 0.028)
		20,000	4.30	147	4.31	0.009	(−0.002 to 0.020)
HCV	1	10,000	4.00	150	4.00	0.000	(−0.020 to 0.019)
		800,000	5.90	150	5.92	0.021	(0.004 to 0.038)
	2	10,000	4.00	150	4.00	0.001	(−0.021 to 0.024)
		800,000	5.90	150	5.93	0.028	(0.009 to 0.046)
	3	10,000	4.00	150	4.01	0.011	(−0.009 to 0.030)
		800,000	5.90	150	5.93	0.031	(0.013 to 0.048)
HIV-1	1	200	2.30	150	2.27	−0.035	(−0.088 to 0.019)
		1,000	3.00	150	2.98	−0.017	(−0.057 to 0.023)
	2	200	2.30	149	2.34	0.036	(−0.001 to 0.072)
		1,000	3.00	149	3.04	0.035	(0.007 to 0.064)
	3	200	2.30	150	2.34	0.043	(0.004 to 0.081)
		1,000	3.00	150	3.04	0.044	(0.015 to 0.073)

^aIU/mL for HBV and HCV; copies/mL for HIV-1.

^bLog₁₀ IU/mL for HBV and HCV; log₁₀ copies/mL for HIV-1.

^cEstimated from the linear equation established by Deming regression method.