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

 产品说明：该提案描述了一项利用城市青少年纵向研究数据进一步研究药物使用的决定因素和后果的计划。以前的研究调查物质使用及其相关的合并症往往集中在个人水平的风险和保护因素。最近的工作设想个人作为社会生态环境的一部分，这促使研究邻里和社区层面的风险和保护因素的影响，我们打算在两个方面建立这一点。首先，从青春期到成年期的过渡是一个快速的生物，认知和社会发展的时期，提出了一种可能性，即一个人对他或她的环境的反应方式，因此它的影响，是年龄依赖性的。具体而言，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负面行为之间的共病水平可能都取决于年龄。第二，调节物质使用率的社会生态环境也可能影响物质使用和其他负面行为之间的联系。这些动态到目前为止还没有被探索，对它们的探索是本提案的目的。为了解决这第一个差距，我们建议使用变系数回归模型来探讨个人和社区层面的物质使用风险因素如何随年龄变化。这不仅会告诉我们什么样的风险/保护因素对药物使用是重要的，而且会告诉我们什么时候它们最重要。为了解决第二个差距，我们将推导出一个以前未探索过的两个二元变量（例如药物使用和武器暴力）之间的依赖性统计模型。在这个模型中-其实现将作为R包免费提供-我们将使用贝叶斯和复合似然方法的组合来隔离比值比的估计-以及它如何作为预测变量的函数而变化-而不需要估计次要参数，例如均值或时间自相关参数。在这个框架内，我们将确定增加/减少物质使用和相关的负面行为之间的共病水平的因素，以及这些关系如何随着年龄的变化。

 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.