School-Based Intervention of Smoking Media Literacy Among South Korean Adolescents: A Cluster Randomized Trial

Purpose: Western literature has well established that (a) exposure to pro-smoking media messages is positively associated with adolescent smoking, and (b) an increase in smoking media literacy (SML) can mitigate the harmful effects of pro-smoking advertisements on adolescent smoking behavior. However, little is currently known about this phenomenon in South Korea. Thus, we aimed to investigate the effects of a SML intervention on SML, smoking attitudes, and smoking norms among Korean adolescents. Methods: Based on the media literacy framework, we developed a five-lesson SML education program. We conducted a cluster randomized trial in one male high school to investigate the effects of the intervention. We randomly allocated ten classes in a one-to-one ratio to either the intervention or control group (N = 250, 10th graders). The intervention group participated in the SML program; the control group participated in a traditional anti-smoking program. We assessed the three outcomes (i.e., SML, smoking attitudes, and norms) at 1-week and 3-month follow-ups. We analyzed data obtained from 249 students after excluding one participant who did not complete the baseline test. Specifically, we conducted a mixed-model regression analysis three times after accounting for intraclass correlations. Results: SML, smoking attitudes, and norms assessed in a pre-test before the intervention did not significantly differ between the intervention and control groups. After the intervention, we found a significant increase in SML at both 1-week (coefficient = .91) and 3-month follow-ups (coefficient = .73), although we did not find important intervention effects on smoking attitudes and norms at both follow-ups. Conclusions: We found a strong effect of the SML education on an increase in SML, which could mitigate the negative effects of pro-smoking advertisements. Thus, health professionals need to actively incorporate strategies that enhance SML, developed based on the multidimensional core concepts of media literacy, into traditional anti-smoking programs. Trial registration: Clinical Research Information Service, KCT0009514.