The development and evaluation of an I-message smoking prevention program for high school students: A randomized controlled trial

Purpose: The purpose of this study was to examine the effect of an I-message-based smoking prevention program for high school students.Methods: The program was developed based on Ajzen’s theory of planned behavior and assertive behavior. The contents of the I-message-based smoking prevention program focused on changes to increase the non-smoking intentions of high school students and to heighten their adjustment to school and was centered on their attitudes toward smoking, subjective norms, and self-efficacy related to smoking denial. The program was composed of eight sessions over four weeks. A nonequivalent control group pretest-posttest design was used. A total of 65 participants were recruited at baseline (33 in the experimental group and 32 in the control group) and 52 participants completed the program. A comparison of attitudes toward smoking, subjective norms, self-efficacy related to smoking denial, assertive behavior, and smoking intention at the baseline and at 4 weeks was conducted.Results: The experimental group showed significant changes in their attitudes toward smoking (Z= -3.15, p=.002), self-efficacy related to smoking denial (Z= -2.99, p=.002), and school adjustment (t=3.62, p=.001) compared to the control group. Conclusion: The I-message-based smoking prevention program had an effect on high school students’ attitudes toward smoking, self-efficacy related to smoking denial, and school adjustment. Therefore, application of this I-message-based smoking prevention program can prevent smoking among high school students.