Institute of Epidemiology & Health Care


Preventing obesity by reducing soft drinks consumption among young people attending dental practices: a feasibility cluster RCT

Author H. Yusuf
Abstract Abstract Background: In England, 70% of young people consume soft drinks on a regular basis which increases the likelihood of obesity and dental caries. Many young people often visit the dentist; however primary dental care has been an underutilised research setting for delivering and evaluating dietary interventions. Motivational Interviewing (MI) has been shown to be effective in behaviour change. Therefore, this study provides an opportunity to assess an obesity intervention to reduce soft drinks consumption among young people attending NHS dental practices. Aims: To conduct a feasibility trial of an MI intervention to reduce soft drinks consumption among young people attending primary dental care practices in North Central London (Camden, Islington, and Haringey). Methods: The initial developmental phase explored dental teams' attitudes, behaviours and perceived barriers in delivering prevention, using a mixed methods approach (focus groups followed by a questionnaire survey). A purposive sample of 11 out of 22 dental practices was selected from the study area for the four focus groups (two with dentists and two with dental care professionals). A cross-sectional survey of all NHS dentists was also conducted using a self-complete questionnaire. Descriptive analysis of the questionnaire data was undertaken and differences by the age and sex of the sample were assessed. A cluster feasibility trial with embedded process evaluation was then undertaken in the second phase of the study. Participants: Ten randomly allocated NHS dental practices recruited 39 overweight or obese young people (11-16 years). Intervention: 3-4 MI sessions. The three main outcomes were: mean daily consumption of sugary soft drinks using a 24 hour dietary recall, body mass index (BMI) and waist circumference. Outcomes were measured at baseline and at 6 month follow-up. Process evaluation outcomes: Recruitment, retention, fidelity and acceptability of the intervention were assessed using mixed methods. MI Fidelity was assessed using the Motivational Interviewing Treatment Integrity Code (MITI). Thematic analysis was used to analyse the qualitative data and descriptive analysis for the quantitative data. The study was approved by the local Ethics Committee (10/H0722/2). Results: Of the 300 eligible respondents, 164 questionnaires were returned (response rate: 54.7%). In Phase I, there were broad similarities in the themes that emerged from the four focus groups and the questionnaire survey. The majority of respondents strongly agreed that NHS dentists had a role to play in smoking cessation counselling, diet and alcohol advice. For dentists, prevention was viewed to be part of their ethical obligation. A high proportion of respondents 95.7% delivered oral hygiene advice, 85.4% provided diet advice, and 76.7% offered smoking cessation advice always or frequently. Barriers to delivering prevention included organisational factors (lack of adequate remuneration, bureaucracy), patient-related factors (motivation and compliance), and clinician-related factors (lack of training and resources). There was significant variation in providing prevention by the age and sex of dentists with female and younger dentists more likely to provide certain aspects of preventive care. Phase II- 10 dental practices were recruited (5 control and 5 intervention). Out of 149 potential participants, 39 (26.2%) conformed to the eligibility criteria, 5 (12.8%) withdrew from the study, and 3 (7.6%) were lost to follow-up, resulting in a retention rate of 79.5%. Facilitators of study implementation included the use of a screening questionnaire, support from the research team and incentives for young people and dental teams. In terms of acceptability, participants reported that the study had a positive impact on their knowledge or behaviours. At follow-up, soft drinks consumption decreased. Dental teams valued being involved in research. They recognised the challenges in recruiting young people and employed varying mechanisms to overcome them. Intervention fidelity revealed the MI practitioners to be proficient in MI and there was little variation in proficiency among the practitioners. Conclusions: Dentists in the study area were actively involved and had a generally positive attitude towards delivering prevention in primary dental care. The intervention was acceptable and feasible among dental teams and young people. MI is a feasible tool for reducing sugary soft drinks consumption among overweight young people attending dental practices. Further research is required to assess its effectiveness in primary dental care.