The Intervening Role of Conversational Frequency and Valence in a School-Based Health Intervention

School-based health interventions are potentially an effective method to communicate health messages to adolescents. Unfortunately, effectiveness of such interventions is limited. Research in other contexts has shown that interpersonal communication can influence the effectiveness of health programs, but this has not been thoroughly tested for school-based health interventions. Therefore, our study investigated interpersonal communication (i.e., conversational valence and frequency) in a school-based intervention context. We used a three-wave randomized-controlled trial with 1056 students to study three aims. The first aim was to investigate the influence of a health intervention on conversational frequency and valence about drinking, snacking, and exercising. Our second aim was to investigate the influence of conversational frequency and valence on (predictors of) drinking, snacking, and exercising. Our third aim was to investigate whether the health intervention indirectly influenced the program outcomes through conversational frequency and valence. Findings showed that conversational frequency and valence were related to (predictors of) the three behaviors. Additionally, findings showed that the intervention did not influence conversational frequency and valence. Accordingly, findings showed no indirect influence of the intervention on program outcomes through conversational frequency and valence. Our findings show the potential of interpersonal communication for health behaviors and predictors; however, they also stress the importance of a health intervention to properly influence interpersonal communication. If health interventions can successfully influence interpersonal communication, intervention effectiveness can be improved.