Theory-based oral health promotion among Hong Kong adolescents

Abstract

Introduction: Oral diseases are preventable through building good oral health behaviors. Health behavior theories provide conceptual frameworks for empirical research into health behavioral change, which may help achieve stable behavioral change for oral disease prevention in adolescents.

Objectives: 1) To systematically investigate the effectiveness of behavioral interventions in improving oral health among adolescents and systematically compare the efficacy between theory-based interventions and conventional interventions; 2) To develop and validate an oral health behavior questionnaire for adolescents based on the Health Belief Model (HBM); and 3) to determine the effectiveness of a theory-based oral health intervention in modifying oral health behaviors and improving oral health among Hong Kong adolescents.

Methods: Behavioral interventions aimed at improving oral health among adolescents were systematically searched from the online databases. The identified studies were synthesized by qualitative summary and/or meta-analysis. After identifying the research gap, a preliminary questionnaire was developed by an expert panel and further validated on 421 Hong Kong secondary school students. The construct validity of the questionnaire was assessed by performing exploratory factor analysis and confirmatory factor analysis. The Cronbach’s alpha coefficient, item-total correlation, and intraclass coefficient were used to test its reliability. A 12-month randomized controlled trial based on HBM/Social Cognitive Theory (SCT) was then conducted among secondary school Grade 2 students in Hong Kong. After the baseline assessment, the intervention group received a peer-led theory-based oral health intervention while the control group received booklets for oral health promotion. Self-reported brushing and flossing, the HBM/SCT constructs, and oral health-related quality of life (OHRQoL) were measured at 6 and 12 months; and dental plaque accumulation and caries status were measured at the 12-month follow-up.

Results: Results from the systematic review showed that plaque index, gingival index, oral health knowledge, and oral health-related behaviors all improved after behavioral interventions. When the duration of observation was extended to over one year, a more effective plaque reduction was found in the theory-guided group (SMD: -0.25, 95% CI: -0.46 ~ -0.04). The final version of the questionnaire consisted of 35 items and the data of the final version fitted the factor analysis model well. The Cronbach’s alpha coefficient for the subscale ( > 0.7), item-total correlations (0.47 ~ 0.91), and the intraclass coefficient (0.82 ~ 0.91) were all above acceptable thresholds. The 12-month randomized controlled trial verified that brushing, flossing and OHRQoL improved more in the experimental group than in the control group at the 6-month follow-up compared with the baseline level (p < 0.001). The mean gain-score difference was 0.81 for brushing, 0.47 for flossing, and -2.51 for OHRQoL at 6 months. At the 12-month follow-up, the mean gain score of brushing frequency, plaque index, caries status, and OHRQoL were 0.18, -0.28, -0.32, and -2.79, respectively, which sustained the significant difference (p < 0.001).

Conclusion: The findings suggested that HBM combined with SCT in a peer-led intervention was more effective than the conventional method to increase self-reported brushing frequency, and to improve oral hygiene status and OHRQoL among Hong Kong adolescents.