The importance of Early Sexual Experiences Among Men Who Have Sex With Men

描述（由申请人提供）：在美国，男男性行为者（MSM）的HIV和细菌性传播感染（STI）发病率是异性恋者的许多倍。尽管人们普遍认为性行为在定义HIV/STI传播动态方面的重要性，但人们对MSM如何形成性行为模式、哪些因素预测这些模式以及这些行为模式在一个人的一生中如何改变知之甚少。我们建议对100名男男性接触者进行队列研究：1)年龄在16-20岁之间，终生有1-3名男性性伴侣，或2)年龄在16-30岁之间，在3年内有过同性性行为。该队列将被跟踪1年，在此期间，参与者将完成关于早期同性恋经历和性行为的基线计算机自我访谈（CASI）；每3个月进行一次回顾性在线随访问卷；网络性爱日记；在基线、6个月和12个月进行艾滋病毒/性传播感染检测。该研究的第一个目的是确定在同性性行为初次发生时招募不同的MSM样本的可行性，对该队列进行为期一年的跟踪调查，收集频繁的性行为数据，并对这些男性进行艾滋病毒/性传播感染检测。成功与否将根据参加和完成研究的男性人数以及完成所有问卷调查和艾滋病毒/性传播感染检测的比例来确定。该研究的第二个目的是评估使用基于网络的性日记来收集性行为数据并确定适当的日记时间表的可行性。男男性行为者将被随机分配日记时间表，我们将根据日记时间表和回顾性问卷数据比较报告的行为频率。最后，对于第三个目标，我们将进行三个分析。首先，我们将评估早期性发育与开始接触同性恋群体的背景之间的关系。其次，我们将调查在一年的随访中观察到的同性初次性行为的背景与风险行为之间的关系。第三，调查人员将进行探索性分析，以确定性行为的模式，如避孕套的使用，艾滋病毒状况的披露，以及性角色和曲目。这些分析将评估个体之间和个体内部的风险如何变化（例如，根据伙伴关系类型），并将寻求建立可在未来更大、更长的队列研究中纵向测量的风险类型。这项研究的发现，以及对男男性接触者性行为的更大规模、更明确的队列研究的发现，可以帮助定义艾滋病毒/性传播感染的传播动态；确定早期同性恋经历中预测随后风险的因素；就预防男男性行为者感染艾滋病毒的干预措施的发展提供见解；为今后的前瞻性干预研究提供平台。公共卫生相关性：2005年，男男性行为者（包括男男性行为者/注射吸毒者）占美国新发艾滋病毒/艾滋病病例的53% （CDC， 2005年）。由于缺乏对早期同性恋经历如何影响随后的风险以及男同性恋者的性行为如何在一个人的一生中发生变化的知识，目前在男同性恋者中开展的科学和预防工作受到了阻碍。我们建议对年轻的、性经验不足的男同性恋者进行一项试点队列研究，以确定对年轻男同性恋者进行大规模前瞻性队列研究的可行性，该研究可能会定义男同性恋的自然史。除了为这项大型研究的设计提供信息外，该研究的结果还可以为数学模型提供经验推导参数，协助设计MSM预防方案，并确定未来干预措施中风险最高的年轻MSM。

DESCRIPTION (provided by applicant): Men who have sex with men (MSM) experience rates of HIV and bacterial sexually transmitted infections (STI) that are many times those experienced by heterosexuals in the U.S. Despite the widely acknowledged importance of sexual behavior in defining HIV/STI transmission dynamics, little is known about how MSM form patterns of sexual behavior, what factors predict these patterns, and how those behavioral patterns change over a person's life. We propose to conduct a cohort study of 100 MSM who are: 1) age 16-20 with 1-3 lifetime male sex partners, or 2) age 16-30 within 3 years of their same-sex sexual debut. This cohort will be followed for 1 year during which participants will complete a baseline computer administered self-interview (CASI) regarding early homosexual experiences and sexual behavior; retrospective online follow-up questionnaires every 3 months; web-based sex diaries; and HIV/STI testing at baseline, 6, and 12 months. The study's first aim is to define the feasibility of enrolling a diverse sample of MSM near the time of same-sex sexual debut, following the cohort for 1 year, collecting frequent sexual behavioral data, and serially testing these men for HIV/STI. Success will be defined based on the number of men who enroll and complete the study, and the proportion who complete all questionnaires and HIV/STI testing. The study's second aim is to assess the feasibility of using web-based sex diaries to collect sexual behavior data and to identify the appropriate diary schedule. MSM will be randomly assigned diary schedules and we will compare the frequency of reported behaviors across diary schedules and against the retrospective questionnaire data. Finally, for the third aim we will conduct three analyses. First, we will asses the association between early sexual development and the context of initiation of contact with the gay community. Second, we will investigate the association between the context of same-sex sexual debut and risk behavior observed throughout the one year of follow-up. Third, investigators will conduct exploratory analyses to define patterns of sexual behaviors such as condom use, HIV status disclosure, and sexual role and repertoire. These analyses will assess how risk varies between individuals and within individuals (e.g., by partnership type), and will seek to establish typologies of risk that can be longitudinally measured in a future, larger and longer cohort study. Findings from the proposed study, as well as those from a larger and more definitive cohort study of MSM sexual behavior, could help define HIV/STI transmission dynamics; identify factors in early homosexual experiences that predict subsequent risk; provide insights into the development of interventions to prevent HIV in MSM; and provide a platform for future prospective intervention studies. PUBLIC HEALTH RELEVANCE: In 2005, MSM (including MSM/IDU) comprised 53% of new HIV/AIDS cases in the U.S (CDC, 2005). Current scientific and prevention efforts among MSM are hampered by the paucity of knowledge about how early homosexual experiences affect subsequent risk, and how the sexual behavior of MSM changes over a person's lifetime. We propose a pilot cohort study of young, sexually inexperienced MSM to define the feasibility of conducting a large, prospective cohort study of young MSM that might define the natural history of male homosexuality. In addition to informing the design of this larger study, findings from the proposed research could provide empirically derived parameters for mathematical models, assist in the design of prevention programs for MSM, and identify the highest risk young MSM for future interventions.