An interventional study of Theory-derived intervention and Conventional health education in Periodontal Diseases and Dental Caries, sponsored by National University of Singapore. Status unknown at 1 site in Singapore. Open to participants aged 55 Years to 70 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2023-03-24.
Sponsored by National University of Singapore · Not applicable, Interventional, and Health services research
Ageing of the world's population is accelerating. Despite the health challenges they face, older people should not be stereotyped as frail and dependent. Healthy ageing is possible if adequate care is provided and effective intervention is delivered for healthy living. Common oral diseases (dental caries and periodontal diseases) are determined to a great extent by health behaviours (diet and oral hygiene) and are controllable through effective interventions. Hence, this study aims to test the theoretical models for health promotion, develop theory-derived intervention, and evaluate its effectiveness in improving oral health of older adults. The study hypothesis is that theory-derived intervention is more effective than conventional health education in eliciting positive behaviours and controlling oral diseases in older adults.
This study targets older adults and aims to (i) test the explanatory power of the dominant theoretical models/ frameworks, (ii) develop theory-derived intervention, and (iii) evaluate the effectiveness of the theory-derived intervention. The hypothesis is that theoretical-derived intervention is more effective than conventional health education in improving oral health behaviours and preventing oral diseases among older adults.
The sample size needed for this study was calculated by using the software G*Power version 3.1.9.2 (Franz Faul, University of Kiel, Germany). The sample size calculation was based on the primary outcomes, namely increment of coronal caries and increment of root caries, and independent t-tests for comparing means of two independent groups. A caries incidence study among the elderly reported that the mean (SD) 5-year caries incidence were 2.65 (3.14) for coronal caries and 2.21 (2.83) for root caries 17. The 2-year incidence of coronal caries and root caries were therefore estimated to be 1.06 (1.26) and 0.88 (1.13), respectively, in the control group. The effect of an intervention is considered clinically significant if it reduces the caries incidence by 40%. Based on a significance level of 5% and a power of 80%, 140 subjects per group are needed for coronal caries and 165 subjects are needed for root caries outcome measures. To take both outcome measures into account, the higher number (i.e., n=165) will be adopted. Allowing for a 25% attrition rate, 220 elderly persons will need to be recruited into each group, giving a total sample size of 440.
Each participant will be required to complete a detailed questionnaire at the initial visit through face-to-face interviews. Information on socio-demographic background (gender, age, education level, past occupation, and type of housing) and oral health behaviours (diet, toothbrushing and dental flossing) will be collected. The questionnaire will also include the scales for three dominant theoretical models, namely, Health Belief Model (HBM), Theory of planned behaviour (TPB) and Social Cognitive Theory (SCT).
The theoretical model that best explains the health behaviours will be selected for designing oral health intervention. Intervention materials and activities will be carefully designed to address all the constructs/ domains of the selected theoretical model(s). Relevant medical literatures will be referred to. The needs, interest, and health literary of the target group (i.e. older adults of varied social and educational backgrounds) will be taken into full consideration. The intervention will be tested in a small group of 15-20 older people to ensure its relevance, practicality, and acceptability.
Participants will be randomly assigned to two groups, stratified by gender and education level. Allocation concealment will be ensured by using sealed opaque envelopes. The two groups will receive conventional health education and theory-derived intervention, respectively.
At baseline and 6-, 12-, and 24-months post-intervention, each participant will a) undergo an oral examination (dental checkup) by a trained dentist, who will be calibrated against an experienced oral epidemiologist and blinded to the group allocation, and b) complete a questionnaire (detailed questionnaire at baseline and short questionnaire for follow-ups). Chi-square tests will be used for comparing proportions. Parametric or non-parametric methods will be adopted for comparing means. ANCOVA (analysis of covariance) and multiple regressions will be performed to evaluate the effects of various factors on the outcomes.
1,109 studies on the registry are indexed under Dental Caries; 197 are open to participants now.
This study's planned enrollment of 440 is above the median of 60 across 916 interventional studies indexed under Dental Caries.
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Exclusion Criteria:
Questionnaire will be used including the scales for three dominant theoretical models, Health Belief Model (HBM), Theory of planned behaviour (TPB) and Social Cognitive Theory (SCT). The theoretical model that best explains the health behaviours of the selected participants will be selected for designing oral health intervention.The theory-derived intervention will address the constructs/domains of the selected model(s) in the context of the three target behaviours (diet, toothbrushing and dental flossing).
Behavioral: Theory-derived intervention
Participants will be randomly assigned to the control group, stratified by gender and education level. Allocation concealment will be ensured by using sealed opaque envelopes.
Behavioral: Conventional health education
The intervention will be delivered through multimedia materials and group activities, as appropriate. Participants will spend approximately 30-45 minutes for the intervention. Intervention materials and activities will be carefully designed to address all the constructs/ domains of the selected theoretical model(s). The effectiveness of the interventions will be evaluated using behavioural outcomes (diet, brushing, flossing) and clinical outcomes (oral hygiene, caries and periodontal conditions).
The conventional health education will be delivered through an oral health talk and oral health booklet. Topics covered are: (i) common oral diseases and its consequences; (ii) common dental problems among older adults; (iii) importance of oral health measures (healthy diet, toothbrushing and dental flossing); and (iv) proper techniques for toothbrushing and dental flossing.
Increment of coronal caries
Number of new surfaces with coronal caries
Time frame: From baseline to 2 years post-intervention
Increment of root caries
Number of new surfaces with root caries
Time frame: From baseline to 2 years post-intervention
Change in dietary behaviours (favourable/unfavourable)
Using a questionnaire, dietary behaviours will be categorised into: 1. favourable (frequency of snack intake, sweet/desert intake and/or sugary drinks \<2times/day) 2. unfavourable (frequency of snack intake, sweet/desert intake and/or sugary drinks \>=2times/day)
Time frame: From baseline to 2 years post-intervention
Change in toothbrushing behaviours (favourable/unfavourable)
Using a questionnaire, toothbrushing behaviours will be categorised as: 1. favourable (frequency of brushing \>=2times/day) 2. unfavourable (frequency of brushing \<2times/day)
Time frame: From baseline to 2 years post-intervention
Change in flossing behaviours (favourable/unfavourable)
Using questionnaire to evaluate frequency of flossing (with \>=once/day considered as favourable and \<once/day considered unfavourable)
Time frame: From baseline to 2 years post-intervention
Change in oral hygiene status (plaque score)
Presence or absence of dental plaque on tooth surfaces
Time frame: From baseline to 2 years post-intervention
Change in periodontal condition
Number of sites with deep periodontal pockets, shallow periodontal pockets, and gingival bleeding only
Time frame: From baseline to 2 years post-intervention
Plan to share: No
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National University of Singapore