Neighbors, ClaytonLewis, Melissa A.Atkins, David C.Jensen, Megan M.Walter, TheresaFossos, NicoleLee, Christine M.Larimer, Mary E.2018-02-262018-02-262010-12Copyright 2010 Journal of Consulting and Clinical Psychology. This is a post-print version of a published paper that is available at: http://psycnet.apa.org/record/2010-19653-001. Recommended citation: Neighbors, Clayton, Melissa A. Lewis, David C. Atkins, Megan M. Jensen, Theresa Walter, Nicole Fossos, Christine M. Lee, and Mary E. Larimer. "Efficacy of Web-Based Personalized Normative Feedback." Journal of Consulting and Clinical Psychology 78, no. 6 (2010): 898-911. doi: 10.1037/a0020766. This item has been deposited in accordance with publisher copyright and licensing terms and with the author’s permission.http://hdl.handle.net/10657/2361Objective: Web-based brief alcohol interventions have the potential to reach a large number of individuals at low cost; however, few controlled evaluations have been conducted to date. The present study was designed to evaluate the efficacy of gender-specific versus gender-nonspecific personalized normative feedback (PNF) with single versus biannual administration in a 2-year randomized controlled trial targeting a large sample of heavy-drinking college students. Method: Participants included 818 freshmen (57.6% women; 42% non-Caucasian) who reported 1 or more heavy-drinking episodes in the previous month at baseline. Participants were randomly assigned in a 2 (gender-specific vs. gender-nonspecific PNF) × 2 (single vs. biannual administration of PNF) + 1 (attention control) design. Assessments occurred every 6 months for a 2-year period. Results: Results from hierarchical generalized linear models provided modest effects on weekly drinking and alcohol-related problems but not on heavy episodic drinking. Relative to control, gender-specific biannual PNF was associated with reductions over time in weekly drinking (d = −0.16, 95% CI [−0.02, −0.31]), and this effect was partially mediated by changes in perceived norms. For women, but not men, gender-specific biannual PNF was associated with reductions over time in alcohol-related problems relative to control (d =−0.29, 95% CI [−0.15,−0.58]). Few other effects were evident. Conclusions: The present research provides modest support for the use of biannually administered web-based gender-specific PNF as an alternative to more costly indicated prevention strategies.en-USAlcoholSocial normsPersonalized normative feedbackPreventionCollege studentsArticle