Probability of a false-negative HIV antibody test result during the window period: a tool for pre- and post-test counselling
Taylor, D.; Durigon, M.; Davis, H.; Archibald, C.; Konrad, B.; Coombs, D.; Gilbert, M.; Cook, D.; Krajden, M.; Wong, T.; Ogilvie, G.
International Journal of Std and Aids 26(4): 215-224
2015
ISSN/ISBN: 1758-1052 PMID: 25033879 DOI: 10.1177/0956462414542987Document Number: 265350
Failure to understand the risk of false-negative HIV test results during the window period results in anxiety. Patients typically want accurate test results as soon as possible while clinicians prefer to wait until the probability of a false-negative is virtually nil. This review summarizes the median window periods for third-generation antibody and fourth-generation HIV tests and provides the probability of a false-negative result for various days post-exposure. Data were extracted from published seroconversion panels. A 10-day eclipse period was used to estimate days from infection to first detection of HIV RNA. Median (interquartile range) days to seroconversion were calculated and probabilities of a false-negative result at various time periods post-exposure are reported. The median (interquartile range) window period for third-generation tests was 22 days (19-25) and 18 days (16-24) for fourth-generation tests. The probability of a false-negative result is 0.01 at 80 days' post-exposure for third-generation tests and at 42 days for fourth-generation tests. The table of probabilities of falsely-negative HIV test results may be useful during pre- and post-test HIV counselling to inform co-decision making regarding the ideal time to test for HIV.