Assessing and Comparing the Short-Term Effects of TPB Only and TPB plus Implementation Intentions Interventions on Snacking Behavior in Iranian Adolescent Girls: A Cluster Randomized Trial. Issue 3 (January 2013)

• Record Type: Journal Article
• Authors: Karimi-Shahanjarini, Akram; Rashidian, Arash; Omidvar, Nasrin; Majdzadeh, Reza
• Is Part Of: American journal of health promotion. Volume 27:Issue 3(2013)
• Page Start: 152
• Page End: 161
• Publication Date: 2013-01
• Subjects: TPB-Based Intervention -- Snacking -- Adolescents -- Implementation Intention -- Prevention Research -- Manuscript format, research -- Research purpose: interventions evaluation -- Study design: three-arm cluster randomized controlled trial -- Outcome measure: intention and snacking behavior -- Setting: school -- Health focus: modify adolescents' snacking behavior -- Strategy: education -- Target population: adolescents -- Target population circumstances: Tehran city; Health promotion -- Periodicals; Health Promotion; Health promotion; Periodicals; Periodicals; 613.05
• DOI: 10.4278/ajhp.110311-QUAN-113
• Languages: English
• ISSNs: 0890-1171

Abstract

Purpose: The evidence for the effectiveness of theory of planned behavior (TPB)–based interventions is mixed. There is also mixed evidence on the effectiveness of adding implementation intentions to TPB-based interventions. In this study we assessed and compared the short-term effects of TPB-only intervention and TPB plus implementation intentions intervention on snacking behavior and intention to consume unhealthy snacks in Iranian adolescent girls. Design: Three-arm cluster randomized controlled trial. Setting: Ten middle schools in Tehran (Iran). Subjects: A total of 29 classes included 739 female adolescents (age range: 12–15 years). Intervention: Two brief interventions including TPB-only intervention and TPB plus implementation intentions intervention. Measures: Food frequency questionnaire and intentions at baseline, 10 days, and 3 months measuring snacking behavior and cognitions about unhealthy snack consumption, respectively. Analysis: Hierarchical linear modeling to assess the interventions' effects. Results: Both interventions successfully decreased intention to consume and consumption of unhealthy snacks at postintervention. Calculation of the effect sizes revealed that the TPB plus implementation intentions intervention was more effective than the TPB-only intervention. The effects remained significant at 3-month follow-up in the TPB plus implementation intentions intervention group only, although the effect size decreased. Conclusion: Overall, the study suggests that adding implementation intentions on top of TPB-based persuasive messages improves effectiveness and sustainability of desirable changes.