Publication Date



Open access

Embargo Period


Degree Type


Degree Name

Doctor of Philosophy (PHD)


Epidemiology (Medicine)

Date of Defense


First Committee Member

Guillermo Prado

Second Committee Member

Daniel J. Feaster

Third Committee Member

Adam Carrico

Fourth Committee Member

Julie Barroso


Sexual minorities represent a diverse group and are characterized by having a sexual identity, attraction or behavior that differs from the majority (i.e., exclusively heterosexual). HIV risk behaviors, in particular substance use, among Hispanic youth and sexual minorities have been well documented, yet little is known about these behaviors in sexual minority Hispanic adolescents (SMHA) specifically. Limited understanding of the mechanisms driving these risk behaviors during adolescence has resulted in a lack of evidence-based interventions targeting these risk behaviors in SMHA. Family relationships have consistently shown to significantly impact these behaviors in both sexual minorities and Hispanic adolescents alike. For example, parental awareness and support of youth’s sexual identity is negatively associated with drug use and condomless sex. Accordingly, the Institute of Medicine has recommended further research to examine the role of family life in SMHA risk behaviors. This dissertation study will use participants of five randomized control trials examining the relative efficacy of the Familias Unidas family-based intervention. By improving family functioning processes such as parent-child communication and parental involvement, the intervention has been efficacious in preventing and reducing drug use and condomless sex in Hispanic adolescents. For this study, participants reporting any sexual contact with a person of the same sex (i.e., SMHA) will be examined. Quantitative data across five studies will be combined and analyzed using integrative data analysis (IDA) methods to account for cohort and study-level differences across trials to minimize bias. This dissertation study will: a) characterize substance use and condomless sex disparities in SMHA and compare to their non-SMHA counterparts; b) test the simultaneous effects of complex social, family and individual level factors on past 90-day substance use and condomless sex among SMHA participants using an ecodevelopmental framework; and c) assess the efficacy of Familias Unidas and the mediating role of family functioning on past 90-day substance use and condomless sex outcomes on SMHA participants. Results from this dissertation study will shed light on the role of family in SMHA sexual and drug risk behaviors to guide the future development or adaption of preventive interventions for SMHA. Relative to non-SMHA, SMHA reported significantly more substance use than non-SMHA, including lifetime cigarette and illicit drug use. Adjusted odds of lifetime use for all substances and past 90-day cigarette use were significantly higher in SMHA. When examining multiple risk and protective factors simultaneously, we found that family functioning was negatively correlated and having substance-using peers was positively correlated and the strongest in predicting past 90-day substance use. We also found a significant indirect effect of higher American acculturation relative to Hispanic cultural practices on past 90-day substance use through family functioning. Finally, our results indicated that Familias Unidas had no significant effect on past 90-day substance use but had a moderate effect on reducing condomless sex in SMHA participants. Collectively, results from this dissertation study provide insight currently lacking in the prevention literature that we expect to promote additional etiologic research and evidence-based action to improve the health and well-being of SMHA.


sexual minority; Hispanic; HIV; family; LGBT; substance