Using structural equation modeling to understand prescription stimulant misuse: a test of the Theory of Triadic Influence

Abstract

Objective: To test a theory-driven model of health behavior to predict the illicit use of prescription stimulants (IUPS) among college students.

Participants: A probability sample of 554 students from one university located in California (response rate=90.52%).

Methods: Students completed a paper-based survey developed with guidance from the Theory of Triadic Influence. We first assessed normality of measures and checked for multicollinearity. A single structural equation model of frequency of IUPS in college was then tested using constructs from the theory's three streams of influence (i.e., intrapersonal, social situation/context, and sociocultural environment) and four levels of causation (i.e., ultimate causes, distal influences, proximal predictors, and immediate precursors).

Results: Approximately 18% of students reported engaging in IUPS during college, with frequency of use ranging from never to 40 or more times per academic term. The model tested had strong fit and the majority of paths specified within and across streams were significant at the p<0.01 level. Additionally, 46% of the variance in IUPS frequency was explained by the tested model.

Conclusions: Results suggest the utility of the TTI as an integrative model of health behavior, specifically in predicting IUPS, and provide insight on the need for multifaceted prevention and intervention efforts.

Keywords: Health behavior theory; Prescription stimulants; Prevention; Substance use.

Figure 1

Abbreviated* structural equation model applying the Theory of Triadic Influence to the Illicit Use of Prescription Stimulants (IUPS) *Note: Abbreviated in that the following were not shown for brevity: 1) paths for indicators of latent variables (circles) and 2) exogenous variables were allowed to freely covary.

Figure 2

Abbreviated* results from the structural equation model applying the Theory of Triadic Influence to the Illicit Use of Prescription Stimulants (IUPS; N = 554 students; Unstandardized Results) *Note: Abbreviated in that 1) paths for indicators of latent variables (circles) were not included and 2) only parameter estimates for significant paths are shown for brevity. Exogenous variables were allowed to freely covary. Details are provided in Table 2. + p <0.10, *p < 0.05, **p < 0.01;