Date of Award

Spring 2012

Document Type


Degree Name

Doctor of Philosophy (PhD)



Committee Director

James M. Henson

Committee Member

Michelle L. Kelley

Committee Member

Cathy Lau-Barraco

Committee Member

James A. Neff


Heavy episodic alcohol use within the college student population is both widespread and problematic (Benton et al., 2004; Core Institute, 2006; Hingson, Zha, & Weitzman, 2009; O'Malley & Johnston, 2002; Perkins, 2002; Singleton, 2007). More than 40% of college students report at least one symptom of alcohol abuse or dependence (Knight et al., 2002). Computerized interventions are widely used because of their advantages over in-person interventions. They are more cost-effective and can quickly deliver tailored individual feedback to more students. Computerized interventions can be administered to large groups of students (e.g., incoming students, athletes, fraternities/sororities). However, a (2007) meta-analysis by Carey and colleagues found that in-person interventions are generally more efficacious than interventions delivered via other mediums.

The current study is a prospective examination of intervention efficacy, the ability of personalized feedback to boost efficacy, and protective behavioral strategies (PBS) as a possible mediator for these relationships. The intervention for the current study, Alcohol 101 Plus™ (Century Council, 2003), incorporates a number of intervention components, including alcohol education, college student drinking norms, skills training, and personalized feedback. The current study sought to improve the efficacy of the online intervention with personalized feedback via email boosters. Content was created based on a comparison of 2-week data to baseline. Boosters provided personalized feedback based on reported alcohol consumption, alcohol-related problems, and PBS use. They included normative data and emphasized PBS. Data were collected from N = 233 college students. Eligibility criteria included drinking 4+ alcoholic drinks within two weeks of the assessment and being between the ages of 18 and 24. Participants were randomized into one of three conditions: 1) control, 2) intervention only, or 3) intervention plus booster. Participants were assessed at baseline (pre-intervention), 2 weeks post, and 4 weeks post. The intervention was administered during the baseline procedure, immediately following assessment. After the 2-week assessment, participants in the intervention-plus-booster condition were sent a booster email.

Piecewise latent growth models revealed no intervention effect among alcohol use indicators or alcohol-related problems. However, knowledge about alcohol and related consequences was significantly increased after the intervention. Interestingly, a significantly indirect effect was found, such that intervention receipt significantly increased growth trajectories for PBS, which in turn was associated with reduced trajectories for alcohol use and related problems. Additionally, the booster emails with personalized feedback had a significant effect. All alcohol use indicators and alcohol-related problems were significantly reduced for those in the experimental booster group. There was limited support for PBS as a mediator of both intervention and booster effects. The implications of these findings are far-reaching, given the prevalence of online interventions targeting college student drinking and the ability of easily-disseminated, cost-effective emails to boost efficacy.