HIV incidence among men who have sex with men prescribed postexposure prophylaxis

摘要

Heuker et al. Found that men who have sex "with men (MSM) who used antiretroviral postexposure prophylaxis (PEP) between 2000 and 2009 have a significantly higher HIV incidence than MSM participating in the Amsterdam Cohort Study (ACS) in the same period: 6.4 vs. 1.6 per 100 person-years, respectively. We argue that the different 'time at risk' used to calculate the incidence could confound comparisons. Indeed, PEP users follow-up was cut-off at 6 months, whereas that of ACS participants was not. This determined a very large difference in the total time under observation that could have diluted the incidence in the ACS: 171 person-years for the 355 PEP users (mean 0.48 person-years) and 4061 person-years for the 782 ACS (mean 5.19 person-years).