Motivational interviewing to promote oral health in adolescents : a randomized controlled trial

Abstract

Background: The control and management of dental caries highly depends on people’s adoption of healthy behaviors. Prevailing health education (PE) usually fails to promote sustained behavioral changes. Motivational interviewing (MI) is a collaborative conversational style for strengthening one’s own motivation and commitment to change and has great potential to change health behaviors.

Objectives: This single-blinded randomized controlled trial investigated the effectiveness of PE, MI, and MI coupled with interactive caries risk assessment (RA) in improving adolescents’ oral health self-efficacy and behaviors and preventing dental caries.

Methods: Fifteen secondary schools were randomly assigned to three groups: (I) PE, (II) MI, and (III) MI+RA. Adolescents aged 12-13 years with unfavorable oral health behavior (“toothbrushing less often than twice a day” AND/OR “snacking three times or more a day”) were eligible to participate. A total of 512 adolescents were recruited; 161, 163 and 188 in Groups I-III respectively. Group I received oral health talks and pamphlets. Each participant in Group II joined a one-on-one, face-to-face MI session with a dental hygienist. In Group III, RA was incorporated to facilitate the MI session. At baseline and after 6, 12, and 24 months, questionnaires were completed to collect information on participants’ sociodemographic background, oral health self-efficacy and behaviors, and dental visits. Participants’ oral hygiene and tooth status were recorded using the Silness-Löe Plaque Index and the International Caries Detection and Assessment System (ICDAS). Intention-to-treat analyses were performed. Generalized linear mixed model was used to account for clustering effect.

Results: There was no significant among-group difference in the sociodemographic, behavioral or clinical variables except for gender, at baseline. After 6, 12 and 24 months, 492 (96.1%), 482 (94.1%) and 460 (89.8%) participants were followed up. At the 24-month follow-up, comparisons with Group I showed that (i) Group II had higher likelihood to change negative self-efficacy in controlling snacking [OR (95% CI): 3.63 (1.02-12.94); p=0.048], whereas the change of negative self-efficacy in brushing was more likely in Group II [OR (95% CI): 4.65 (1.86-11.63)] and Group III [OR (95% CI): 4.30 (1.74-10.64)]; (ii) restriction of frequent snacking was more likely in Group II [OR(95% CI): 3.91 (1.48-10.33)] and Group III [OR(95% CI): 6.33 (2.46-16.27)], whereas participants in Group III were more likely to adopt the behavior of brushing twice a day [OR (95% CI) of 4.80 (1.79-12.85)]; (iii) there was no significant difference in plaque score reduction across three groups (p>0.05); and (iv) Groups II and III developed fewer cavitated carious teeth (△DICDASII 3-6MFT) [β (95% CIs): -0.19 (-0.37, -0.01) and -0.20 (-0.38, -0.02) respectively], whereas increment of teeth with caries experience (△DICDASII 1-6MFT) was lower in Group III [β (95% CI): -0.63(-1.24, -0.02)]. The 6- and 12-month results showed similar trends.

Conclusions: Motivational interviewing is more effective than prevailing health education in enhancing adolescents’ oral health self-efficacy, improving their oral health behaviors, and preventing dental caries. Incorporation of caries risk assessment can improve some outcomes and should be considered if conditions allow.