Substance use, violence and HIV risk: Age-specific risk factors and drivers of comorbidity.

 描述：这项建议描述了一项计划，利用对城市青少年的纵向研究数据，进一步研究物质使用的决定因素和后果。以前调查药物使用及其相关并发症的研究往往集中在个体水平的风险和保护因素上。最近的工作将个人视为社会生态背景的一部分，这促使我们研究邻里和社区层面的风险和保护因素的影响，我们打算在这基础上采取两种方式。首先，从青春期到成年期是一个生物、认知和社会快速发展的时期，这表明一个人对他或她的环境的反应方式以及由此产生的影响可能与年龄有关。具体地说，由于特定年龄的发展和社会背景，物质使用率、哪些变量作为物质使用的风险/保护因素以及物质使用和其他消极行为之间的共病程度都可能与年龄有关。其次，被发现调节物质使用率的相同社会生态背景也可能影响物质使用与其他负面行为之间的联系。到目前为止，这些动态还没有得到探索，而本提案的目的就是探索它们。为了解决第一个差距，我们建议使用变系数回归模型来探索个人和社区层面的危险因素对药物使用的影响如何随年龄变化。这不仅会告诉我们哪些物质使用的风险/保护因素是重要的，而且会告诉我们它们何时是最重要的。为了解决第二个差距，我们将推导出一个以前没有探索过的关于两个二元变量(例如，物质使用和武器暴力)之间相关性的统计模型。在这个模型中-它的实现将以R包的形式免费提供-我们将使用贝叶斯和复合似然方法的组合来分离对赔率比的估计-以及它作为预测变量的函数的变化-而不需要估计次要感兴趣的参数，如均值或时间自相关参数。在这个框架内，我们将确定增加/减少药物使用和相关负面行为之间共病水平的因素，以及这些关系如何随着年龄的变化而变化。

 DESCRIPTION: This proposal describes a plan to further study the determinants and consequences of substance use using data from a longitudinal study of urban adolescents. Previous studies investigating substance use and its associated comorbidities often focus on individual-level risk and protective factors. More recent work has envisioned individuals as part of a socio-ecological context, which motivates studying the effects of neighborhood- and community-level risk and protective factors and we intend to build on this on two ways. First, The transition from adolescence to adulthood is a period of rapid biological, cognitive and social development, presenting the possibility that the way an individual reacts to his or her environment, and therefore the effect it has, is age-dependent. Specifically, due to age-specific developmental and societal context, it is likely that rates of substance use, what variables operate as risk/protective factors for substance use, and the level of comorbidity between substance use and other negative behaviors are all age-dependent. Second, the same socio-ecological context that been found to modulate substance use rates may also affect the link between substance use and other negative behaviors. These dynamics have gone unexplored to this point and their exploration is the purpose of this proposal. To address this first gap, we propose using varying coefficient regression models to explore how the effects of individual- and community- level risk factors for substance use change with age. This will tell us not only what risk/protective factors for substance use are important, but when they are most important. To address the second gap, we will derive a previously unexplored statistical model of the dependence between two binary variables (e.g. substance use and weapon violence). In this model - whose implementation will be made freely available as an R package - we will use a combination of Bayesian and composite likelihood approaches to isolate estimation of the odds ratio - and how it changes as a function of predictor variables - without the need to estimate parameters of secondary interest, such as means or temporal autocorrelation parameters. Within this framework, we will determine the factors that increase/decrease the level of comorbidity between substance use and related negative behaviors, as well as how these relationships change with age.