title: Efficacy of web-based personalized normative feedback: a two-year randomized controlled trial.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
authors.affiliation: Department of Psychiatry & Behavioral Sciences, University of Washington, USA. cneighbors@uh.edu
authors.forename: Clayton
authors.initials: C
authors.lastname: Neighbors
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Lewis
authors.forename: David C
authors.initials: DC
authors.lastname: Atkins
authors.forename: Megan M
authors.initials: MM
authors.lastname: Jensen
authors.forename: Theresa
authors.initials: T
authors.lastname: Walter
authors.forename: Nicole
authors.initials: N
authors.lastname: Fossos
authors.forename: Christine M
authors.initials: CM
authors.lastname: Lee
authors.forename: Mary E
authors.initials: ME
authors.lastname: Larimer
mesh_terms: D000437:Alcoholism / Q000517:prevention & control* / Q000523:psychology / Q000628:therapy; D005246:Feedback; D005260:Female; D006801:Humans; D020407:Internet; D008297:Male; D012737:Sex Factors; D013334:Students; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014495:Universities; D055815:Young Adult