The Kirby Institute, UNSW Sydney, New South Wales, Australia.
Australian Research Centre in Sex Health and Society, La Trobe University, Melbourne, Victoria, Australia.
J Acquir Immune Defic Syndr. 2019 May 1;81(1):52-56. doi: 10.1097/QAI.0000000000001976.
HIV pre-exposure prophylaxis (PrEP) has been increasingly adopted by gay and bisexual men (GBM). Little is known about whether individual GBM change their sexual behavior after PrEP initiation.
Following Lives Undergoing Change (Flux) is a national, online, prospective observational study among Australian GBM. Using McNemar statistics, we compare rates of sexual behaviors before and coincident with PrEP initiation among 1518 non-HIV-positive men recruited between August 2014 and July 2017 who had not commenced PrEP at baseline and who completed at least one 6-monthly follow-up surveys by July 2018.
The proportion of men using PrEP rose to 24.2% over time. In total, 348 men initiated PrEP during follow-up. PrEP initiators were more likely to report particular sexual behaviors during the follow-up period that they commenced PrEP compared with the period immediately prior: receptive condomless anal intercourse with casual partners increased from 31.0% to 48.9% (McNemar < 0.001); mean partner number increased from 21.96 partners to 34.55 partners (p-trend < 0.001). Among the 1170 men who did not initiate PrEP, prevalence of these behaviors remained lower and stable. Sexual sensation-seeking and gay social engagement were both higher among men who commenced PrEP.
GBM tended to increase their engagement in "adventurous" sexual behaviors after PrEP initiation. Sexual behaviors among men who did not initiate PrEP were less common and did not change over time.
艾滋病毒暴露前预防（PrEP）已被男同性恋和双性恋者（GBM）越来越多地采用。人们对 PrEP 启动后个体 GBM 是否改变性行为知之甚少。
在澳大利亚 GBM 中进行的全国性、在线、前瞻性观察性研究，称为生活在变化中（Flux）。使用 McNemar 统计，我们比较了 1518 名未感染 HIV 的男性在基线时未开始 PrEP 且在 2018 年 7 月之前至少完成了一次 6 个月随访调查的人群，在 PrEP 启动前后的性行为发生率。
随着时间的推移，使用 PrEP 的男性比例上升至 24.2％。总共有 348 名男性在随访期间开始使用 PrEP。与 PrEP 启动前相比，PrEP 启动者在随访期间更有可能报告某些性行为：与偶然伴侣进行的接受性无保护肛交从 31.0％增加到 48.9％（McNemar <0.001）；伴侣数量从平均 21.96 人增加到 34.55 人（p 趋势<0.001）。在未开始 PrEP 的 1170 名男性中，这些行为的流行率仍然较低且稳定。开始 PrEP 的男性的性感觉寻求和同性恋社交参与度均较高。
GBM 在开始 PrEP 后倾向于增加其参与“冒险”性行为。未开始 PrEP 的男性的性行为较少，且随时间变化不大。
