Sexually transmitted infections (STIs) remain an important public health concern for people of all age groups, with older age groups experiencing a notable increase in STI burden. Historically, most research into STI risk behaviors has focused on adolescents and young adults, leaving a paucity of research on the ways STI risk factors change over the life course. Additionally, age and cohort trends in STI risk factors can be challenging to investigate with standard statistical tools as they can be collinear and are subject to sociocultural and generational influences. To help address these issues, we used multi-group latent class analysis to identify and compare risk behavior profiles defined by responses to three sexual activity and three substance use variables, across and within four age groups. We identified six behavior profiles in the unstratified dataset and five behavior profiles in each of the four age stratified groups. The five behavior profiles identified in each of the age categories appear to reflect a similar set of five underlying profile “archetypes,” with the exact composition of each age category’s five profiles varying in the magnitude that specific behaviors are endorsed. Interestingly, despite the similarity of profiles across the four age groups, analyses indicate that the experience of belonging to any one of these five archetypes differs by age group. This variance is likely due group specific age, period, and cohort effects, and may indicate that, when estimating one’s STI risk, it is better to compare them to their peers than to the population as a whole.

性传播感染（STI）仍然是所有年龄段人群的一个重要公共卫生问题，其中老年群体的性传播感染负担显着增加。从历史上看，大多数对性传播感染风险行为的研究都集中在青少年和年轻人，而对性传播感染风险因素在生命过程中如何变化的研究却很少。此外，使用标准统计工具调查性传播感染风险因素的年龄和队列趋势可能具有挑战性，因为它们可能是共线的，并且受到社会文化和代际影响。为了帮助解决这些问题，我们使用多组潜在类别分析来识别和比较四个年龄组之间和内部对三种性活动和三种物质使用变量的反应所定义的风险行为特征。我们在未分层数据集中确定了六个行为概况，在四个年龄分层组中每个群体中确定了五个行为概况。每个年龄类别中确定的五个行为概况似乎反映了一组相似的五个基本概况“原型”，每个年龄类别的五个概况的确切组成因特定行为被认可的程度而异。有趣的是，尽管四个年龄组的概况相似，但分析表明，属于这五种原型中任何一种的体验因年龄组而异。这种差异可能是由于群体特定年龄、时期和队列效应造成的，并且可能表明，在估计一个人的性传播感染风险时，最好将他们与同龄人进行比较，而不是与整个人群进行比较。