Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
Northwestern University Institute for Sexual and Gender Minority Health and Wellbeing, Chicago, IL, USA.
Arch Sex Behav. 2019 May;48(4):1099-1110. doi: 10.1007/s10508-019-1407-8. Epub 2019 Mar 19.
Young men who have sex with men (YMSM) have the highest HIV incidence in the U.S. The last 5 years has seen emergence of new methods for HIV prevention and societal shifts in gay rights. It is important to understand if there have been generational shifts in condom use during the developmental transition from adolescents to young adulthood. To disentangle history from development, we require a multiple-cohort, longitudinal design-a methodology never before applied to study YMSM. We followed three cohorts of YMSM recruited in 2007, 2010, and 2015 (N = 1141) from the ages of 17-26 years and modeled their longitudinal change over time in counts of anal sex acts and the ratio of condomless anal sex (CAS) acts to anal sex acts using latent curve growth modeling. We found that there was no significant developmental change in raw counts of anal sex acts, but there was a significant decline in the ratio of anal sex acts that were condomless. We also found significantly different patterns for ratio of CAS acts for the 2015 cohort. The 2015 cohort reported a significantly lower ratio of CAS acts at age 17, but significantly higher growth in ratio of CAS acts over development. The present study suggests that YMSM recruited in 2015 have very different trajectories of CAS compared to previous cohorts, including lower risk in late adolescence, but with the potential for higher risk after the transition into adulthood.
男男性行为者（MSM）的 HIV 发病率在美国是最高的。在过去的 5 年中，出现了新的 HIV 预防方法和同性恋权利方面的社会转变。了解青少年到成年期的发展过渡过程中， condom（避孕套）的使用是否存在代际变化是很重要的。为了将历史与发展分开，我们需要采用多队列、纵向设计——一种从未应用于研究 MSM 的方法。我们跟踪了三个队列的 MSM，他们于 2007 年、2010 年和 2015 年（N=1141）从 17 岁到 26 岁招募，使用潜在曲线增长建模来模拟他们在肛交行为次数和无保护肛交行为（CAS）与肛交行为之比方面的纵向随时间变化。我们发现，肛交行为的原始计数没有明显的发展变化，但无保护肛交行为的比例有显著下降。我们还发现，2015 队列的 CAS 行为比率模式存在显著差异。2015 队列在 17 岁时报告的 CAS 行为比率明显较低，但在发展过程中，CAS 行为比率的增长明显较高。本研究表明，与之前的队列相比，2015 年招募的 MSM 的 CAS 轨迹非常不同，包括青春期后期的风险较低，但成年期过渡后风险可能更高。
