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- All Subjects: Mexican American teenagers--Mental health.
- All Subjects: Quantitative Psychology and Psychometrics
- Creators: Barrera, Manuel
- Member of: ASU Electronic Theses and Dissertations
Description
Random Forests is a statistical learning method which has been proposed for propensity score estimation models that involve complex interactions, nonlinear relationships, or both of the covariates. In this dissertation I conducted a simulation study to examine the effects of three Random Forests model specifications in propensity score analysis. The results suggested that, depending on the nature of data, optimal specification of (1) decision rules to select the covariate and its split value in a Classification Tree, (2) the number of covariates randomly sampled for selection, and (3) methods of estimating Random Forests propensity scores could potentially produce an unbiased average treatment effect estimate after propensity scores weighting by the odds adjustment. Compared to the logistic regression estimation model using the true propensity score model, Random Forests had an additional advantage in producing unbiased estimated standard error and correct statistical inference of the average treatment effect. The relationship between the balance on the covariates' means and the bias of average treatment effect estimate was examined both within and between conditions of the simulation. Within conditions, across repeated samples there was no noticeable correlation between the covariates' mean differences and the magnitude of bias of average treatment effect estimate for the covariates that were imbalanced before adjustment. Between conditions, small mean differences of covariates after propensity score adjustment were not sensitive enough to identify the optimal Random Forests model specification for propensity score analysis.
ContributorsCham, Hei Ning (Author) / Tein, Jenn-Yun (Thesis advisor) / Enders, Stephen G (Thesis advisor) / Enders, Craig K. (Committee member) / Mackinnon, David P (Committee member) / Arizona State University (Publisher)
Created2013
Description
Recent reports have indicated that there are both mental health and educational disparities between Latino youth and their European American counterparts. Specifically, Latin youth are at a heightened risk for negative mental health outcomes in comparison to their non-Latino youth (e.g., Eaton et al., 2008). Further, 16.7% of Latino adolescents dropped out of high school compared to 5.3% of European American youth over the past several decades (1960-2011; U.S. Department of Education, 2013). Mexican American (M.A. youth in particular, have the lowest educational attainment among all Latino ethnic groups in the U.S. (U.S. Census Bureau, 2010). While these mental health and educational disparities have often been attributed to discrimination experiences that Latino youth encounter, there is also consistent empirical evidence linking discrimination with these maladjustment problems. These studies confirmed that discrimination directly related to depressive symptoms (e.g., Umana-Taylor et al., 2007), externalizing behaviors (Berkel et al., 2010), self-esteem (e.g., Zeiders et al., 2013), and academic outcomes (e.g., Umana-Taylor et al., 2012). Few studies to date have examined the underlying mechanisms (i.e., moderation and mediation) that help us to better understand resiliency paths for those Latino youth that display positive adjustment outcomes despite being faced with similar discrimination encounters that their maladjusted peers face. Therefore, the following two studies examined various mechanisms in which discrimination related to adjustment to better understand potential risk and resiliency processes in hopes of informing intervention research. Paper 1 explored cultural influences on the association between discrimination, active coping, and mental health outcomes in M.A. youth. Paper 2 examined how trajectories of discrimination across 5th, 7th, and 10th grades related to cultural values, externalizing behaviors, and academic outcomes in M.A. youth. Taken together, these studies provide a culturally informed overview of adjustment processes in M.A. adolescents who face discrimination in addition to identifying critical directions for future research in efforts to gaining a more contextualized and comprehensive understanding of the dynamic processes involved in discrimination and adjustment in M.A. youth.
ContributorsO'Donnell, Megan (Author) / Roosa, Mark W. (Thesis advisor) / Dumka, Larry (Committee member) / Gonzales, Nancy (Committee member) / Barrera, Manuel (Committee member) / Arizona State University (Publisher)
Created2014
Description
Mexican American adolescents report high rates of internalizing symptomatology and alcohol use. However, very little research has explored to what extent internalizing distress may contribute to alcohol use among this population. The current study utilized longitudinal data from a community sample of Mexican American adolescents (n=626, 51% female) to test a series of hypotheses about the role of internalizing distress on alcohol use and misuse. Specifically, this study used a bifactor modeling approach to investigate (1) whether different forms of internalizing distress are composed of common and unique components; (2) whether and to what extent such components confer risk for alcohol use; and (3) whether youth cultural orientation plays a role in these associations. Confirmatory factor analyses revealed that a bifactor model with a general factor and three specific factors (depressed mood, general worry, social anxiety) provided good fit to the data. The general distress factor was significantly associated with past month alcohol use but not binge drinking. However, these effects were conditional based on level of acculturation. Differential relations were found between the specific factors of internalizing distress and alcohol use. Depressed mood predicted past month alcohol use among girls; social anxiety negatively predicted past three month binge drinking among boys. Overall, results highlight the multidimensional nature of internalizing distress and suggest that both common and unique components of internalizing distress may be relevant to the etiology of alcohol use among Mexican-American adolescents. Findings underscore the importance of considering cultural orientation as a moderating factor when investigating substance use among Hispanic youth. Implications for future research examining the etiological relevance of the internalizing pathway to alcohol use among Hispanic adolescents are discussed.
ContributorsNichter, Brandon (Author) / Gonzales, Nancy (Thesis advisor) / Chassin, Laurie (Committee member) / Barrera, Manuel (Committee member) / Tein, Jenn (Committee member) / Arizona State University (Publisher)
Created2018
Description
Item response theory (IRT) and related latent variable models represent modern psychometric theory, the successor to classical test theory in psychological assessment. While IRT has become prevalent in the assessment of ability and achievement, it has not been widely embraced by clinical psychologists. This appears due, in part, to psychometrists' use of unidimensional models despite evidence that psychiatric disorders are inherently multidimensional. The construct validity of unidimensional and multidimensional latent variable models was compared to evaluate the utility of modern psychometric theory in clinical assessment. Archival data consisting of 688 outpatients' presenting concerns, psychiatric diagnoses, and item level responses to the Brief Symptom Inventory (BSI) were extracted from files at a university mental health clinic. Confirmatory factor analyses revealed that models with oblique factors and/or item cross-loadings better represented the internal structure of the BSI in comparison to a strictly unidimensional model. The models were generally equivalent in their ability to account for variance in criterion-related validity variables; however, bifactor models demonstrated superior validity in differentiating between mood and anxiety disorder diagnoses. Multidimensional IRT analyses showed that the orthogonal bifactor model partitioned distinct, clinically relevant sources of item variance. Similar results were also achieved through multivariate prediction with an oblique simple structure model. Receiver operating characteristic curves confirmed improved sensitivity and specificity through multidimensional models of psychopathology. Clinical researchers are encouraged to consider these and other comprehensive models of psychological distress.
ContributorsThomas, Michael Lee (Author) / Lanyon, Richard (Thesis advisor) / Barrera, Manuel (Committee member) / Levy, Roy (Committee member) / Millsap, Roger (Committee member) / Arizona State University (Publisher)
Created2011