Advancing measurement and scoring methods for testing mediation models of substance use - PROJECT SUMMARY/ABSTRACT Research on the intergenerational transmission of substance use seeks to identify the various mechanisms or mediators which connect parental substance use, an established risk factor, to adolescent substance use. Parent-related mediators are measured using multiple informant data, which allows for a comprehensive assessment of behaviors and reduces bias from any single reporter. However, current methods for analyzing multiple informant data in mediation models do not separate the different sources of variance present in multiple informant ratings, meaning that the variance that is unique to each parent is confounded with the variance that is common across both parents. As a result, the estimates for mediated effects become biased, and effects that are caused by one source of variance (e.g., the common behaviors between parents) may be misattributed to a different source of variance (e.g., maternal-specific behaviors). As a consequence, our understanding of intergenerational processes and ability to design effective preventive interventions is limited. To address these limitations, a recently developed psychometric model, the trifactor model (TFM) can be used to disentangle the sources of variance present in multiple informant data, allowing for more accurate estimates of mediated effects, and more valid and specific substantive conclusions about the intergenerational processes therein. The TFM separates the sources of variance in multiple informant data into three independent levels: a common factor representing the shared variability across reporters, the perspective factors representing the variability unique to each reporter, and the specific factors representing variance arising from the use of the same items. Despite the great potential of the TFM, this model has not yet been evaluated within a mediation model, nor compared to current methods. Moreover, this model is complex and most applications would require latent variable scores in order to reduce the number of parameters, but there are a number of challenges to obtaining scores for this model that would need to be addressed. In order to expand the applicability of the TFM, the proposed research will (1) derive a single mediator model with the TFM and compare performance to traditional multiple-informant methods, (2) extend the TFM to parallel mediation model and develop factor scoring approaches, and (3) Apply novel TFM methods to empirical data to examine parental monitoring as a mediator for the intergenerational transmission of substance use. The current NRSA proposal presents a novel expansion of the TFM so that it may be used to uncover specific mechanisms that lead to adolescent substance use. Further, this fellowship will provide the crucial training needed to establish this applicant's independent research program in developing quantitative methods for the study of adolescent substance use and prevention through training in statistical mediation, family-based models of substance use, prevention science, and research dissemination.
