HIV infection in Xi’an, China: epidemic characterization, risk factors to false positives and potential utility of the sample-to-cutoff index to identify true positives using Architect HIV Ag/Ab combo

Table 2 Consistency and PPV at different COI values for HIV screening

First-test-reactive (Ag/Ab Combo)		Retesting by 3rd-generation			PPV (%)
Groups (COI Values)	N0.	Reactive (TP)	Non-reactive (TP)	Consistency(%)	PPV (%)
L (1.00–10.00)	93	2 (0)	91 (0)	2.15	0
M (10.00–30.00)	14	12 (6)	2 (1)	85.71	50
H (≥30.00)	110	110 (110)	0	100	100
Total	217	124 (116)	93 (1)	57.14	53.92

ISSN: 2047-2994