Malone Patrick S, Lamis Dorian A, Masyn Katherine E, Northrup Thomas F
University of South Carolina.
Multivariate Behav Res. 2010 Sep 1;45(5):790-805. doi: 10.1080/00273171.2010.519277.
The gateway drug model is a popular conceptualization of a progression most substance-users are hypothesized to follow as they try different legal and illegal drugs. Most forms of the gateway hypothesis are that "softer" drugs lead to "harder," illicit drugs. However, the gateway hypothesis has been notably difficult to directly test - i.e., to test as competing hypotheses in a single model that licit drug use might lead to illicit drug use or the reverse. This article presents a novel statistical technique, dual-process discrete-time survival analysis, which enables this comparison. This method uses mixture-modeling software to estimate two concurrent time-to-event processes and their effects on each other. Using this method, support for the gateway hypothesis in the National Longitudinal Survey of Youth 1997 was weak. However, this paper was not designed as a strong test of causal direction but more as a technical demonstration, and suffered from certain technological limitations. Both these limitations and future directions are discussed.
致瘾药物模型是一种流行的概念化表述，用于描述大多数药物使用者在尝试不同合法和非法药物时被假定遵循的一种递进过程。致瘾药物假说的大多数形式认为，“较温和”的药物会导致“更烈性”的非法药物使用。然而，致瘾药物假说一直很难直接进行检验——也就是说，在一个单一模型中作为相互竞争的假说进行检验，即合法药物使用可能导致非法药物使用，或者反之。本文提出了一种新颖的统计技术，双过程离散时间生存分析，它能够进行这种比较。该方法使用混合建模软件来估计两个并发的事件发生时间过程及其相互影响。使用这种方法，在1997年全国青年纵向调查中对致瘾药物假说的支持力度较弱。然而，本文并非设计用于对因果方向进行强有力的检验，而更多地是作为一种技术演示，并且存在某些技术局限性。本文将讨论这些局限性以及未来的研究方向。
