Using the Transtheoretical Model of Change to Enhance High School Female Students’ Self-Efficacy of Refraining from Carbonated Drinks Consumption

Objectives: To examine the efficacy of the Transtheoretical Model of Change-based intervention in enhancing students’ Self-Efficacy by refraining from carbonated drinks. Methods: We conducted a randomized controlled trial at Al-Russafa High School for girls in Baghdad City. The study involved a random sample of 144 female high school students, with 72 students in the intervention group and 72 in the control group. The research instrument collected data on participants' sociodemographic characteristics, including age, living arrangements, and family socioeconomic status. Additionally, we used the Stages of Change for Carbonated Drinks Consumption Behaviour Scale (Short Form) and the Stages of Change for Carbonated Drinks Consumption Behaviour Scale (Continuous Measure). Data analysis was performed using the Statistical Package for Social Science (SPSS) for Windows, version 27. Results: The study results exhibit that more than half of participants in the study group are in the Precontemplation Stage of Change in the pretest time (n = 42; 58.3%), followed by those who are in the Preparation Stage of Change (n = 15; 20.8%), those who are in the Contemplation Stage of Change (n = 14; 19.4%), and one who is in the Maintenance Stage of Change (n = 1; 1.4%). In posttest 2, less than two-fifths became in the Action Stage of Change (n = 28; 38.9%), followed by those who became in the Preparation Stage of Change (n = 19; 26.4%), those who became in the Maintenance Stage of Change (n = 18; 25.0%), those who became in the Contemplation Stage of Change (n = 6; 8.3%), and one who stayed in the Precontemplation of Change (n = 1; 1.4%). The researchers concluded that the administered intervention based on the TTM efficaciously enhanced students’ readiness to refrain from carbonated drinks consumption. Conclusion: The administered Stage-matched intervention based on the TTM efficaciously enhanced students’ Self-Efficacy in refraining from carbonated drinks consumption.