The efficacy of peer-led oral health programs based on Social Cognitive Theory and Health Belief Model among Hong Kong adolescents: a cluster-randomized controlled trial

Oral diseases are preventable through the building of good oral health behaviors. Theory-based behavior change was key to the efficacy of oral health promotion since conventional promotion strategies achieved only short-lived and limited improvements. The objective of the study was to investigate the efficacy of a peer-led oral health intervention based on the health belief model (HBM) and the social cognitive theory (SCT) on oral self-care behaviors among Hong Kong adolescents. One thousand one hundred and eighty-four adolescents in 12 schools participated and were randomly assigned to either intervention or control group, utilizing a cluster-randomized controlled trial design. Brushing/flossing frequency, HBM/SCT constructs, oral health knowledge, and dental anxiety were measured at baseline and 6-month follow-up. Changes in behaviors were assessed using mixed-effects model and the mediators of behavioral change were identified with parallel multiple mediation analysis. At 6 months, the intervention group showed a significant increase in the frequency of brushing and flossing compared with the control group. Self-efficacy was identified as mediator between treatment condition and behavioral changes of brushing and flossing. Combining theories of HBM and SCT is a promising avenue for efficacy in oral health behaviors. The effects were mediated through cognitive variables, which provided guidance for both theory and health intervention development.