Testing mediating variables in a school-based nutrition intervention program.

This study identified mediators of a school-based nutrition intervention for 4th graders and their parents. Nine variables were tested for satisfying 4 conclusions necessary to establish mediation of intervention effects on changes in fruit and vegetable consumption (FVC) in 4th graders (N = 1,676). FVC was measured in children by the use of 24-hr dietary recalls. Mediators were assessed by the use of questionnaires completed by children and parents. All 4 conclusions were met for positive outcome expectancies. Knowledge, self-efficacy, and parent consumption satisfied the first 3 conclusions for mediation but the mediating effects were not statistically significant (Conclusion 4). Future mediational analyses and the creation of a national database of mediators are crucial for increasing strength and efficiency of school-based nutrition programs.     

Mediation of a middle school skin cancer prevention program.

This study tested potential mediators of a school-based skin cancer prevention intervention for middle school children (6th-8th grades; N = 1,788). Ten variables were tested on 4 criteria to establish mediation, including (a) intervention related to outcome, (b) intervention related to mediators, (c) mediators related to outcome, and (d) mediated effect statistically significant. Sun-safe behaviors (e.g., sunscreen use) and potential mediators were measured with a self-report questionnaire. All criteria were met for Barriers--Sunscreen, Perceived Self-Efficacy, and Knowledge when the mediators were tested separately. In multiple mediator analyses, barriers to sunscreen use and self-efficacy satisfied Criteria 1-3 but were not statistically significant (Criterion 4). Barriers to sunscreen use, perceived self-efficacy for sun-safe behavior, and knowledge may serve as mediators.