Fluoride Action Network

CHILDSMILE. Evaluation of a national complex oral health improvement programme: a population data linkage cohort study in Scotland.

Source: BMJ 10:e038116. | Authors: Kidd JBR, McMahon AD, Sherriff A, et al.
Posted on November 24th, 2020


Objectives Child dental caries is a global public health challenge with high prevalence and wide inequalities. A complex public health programme (Childsmile) was established. We aimed to evaluate the reach of the programme and its impact on child oral health.

Setting Education, health and community settings, Scotland-wide.

Interventions Childsmile (national oral health improvement programme) interventions: nursery-based fluoride varnish applications (FVAs) and supervised daily toothbrushing, community-based Dental Health Support Worker (DHSW) contacts and primary care dental practice visits—delivered to the population via a proportionate universal approach.

Participants 50 379 children (mean age=5.5 years, SD=0.3) attending local authority schools (2014/2015).

Design Population-based individual child-level data on four Childsmile interventions linked to dental inspection survey data to form a longitudinal cohort. Logistic regression assessed intervention reach and the independent impact of each intervention on caries experience, adjusting for age, sex and area-based Scottish Index of Multiple Deprivation (SIMD).

Outcome measures Reach of the programme is defined as the percentage of children receiving each intervention at least once by SIMD fifth. Obvious dental caries experience (presence/absence) is defined as the presence of decay (into dentine), missing (extracted) due to decay or filled deciduous teeth.

Results 15 032 (29.8%) children had caries experience. The universal interventions had high population reach: nursery toothbrushing (89.1%), dental practice visits (70.5%). The targeted interventions strongly favoured children from the most deprived areas: DHSW contacts (SIMD 1: 29.5% vs SIMD 5: 7.7%), nursery FVAs (SIMD 1: 75.2% vs SIMD 5: 23.2%). Odds of caries experience were markedly lower among children participating in nursery toothbrushing (>3 years, adjusted OR (aOR)=0.60; 95% CI 0.55 to 0.66) and attending dental practice (>6 visits, aOR=0.55; 95% CI 0.50 to 0.61). The findings were less clear for DHSW contacts. Nursery FVAs were not independently associated with caries experience.

Conclusions The universal interventions, nursery toothbrushing and regular dental practice visits were independently and most strongly associated with reduced odds of caries experience in the cohort, with nursery toothbrushing having the greatest impact among children in areas of high deprivation.


Strengths and limitations of the study

  • This is the first population-wide data linkage cohort study to evaluate the reach and impact of a complex public health intervention.

  • There is evidence of effectiveness of oral health improvement interventions for children including fluoride toothpaste and professionally applied fluoride varnish; however, the evidence of combining these into a complex oral health improvement programme delivered via a proportionate universal approach has not previously been evaluated.

  • The study uses routine administrative data, which have some limitations in the variables available, including a lack of information on intermediate individual behaviours.

  • The outcome data available, the presence or absence of obvious dental caries experience, collected by trained and standardised dental inspection teams and available at the population level show a high level of agreement with detailed decay, missing, and filled teeth (dmft) index scores collected by calibrated dental inspection teams on a much smaller sample of children.

  • The study strengths are in the robust data linkage approach, where there were no concerns about the quality and completeness of the data linkage, resulting in a cohort with population-wide coverage of outcome and intervention data.


Oral health is a global public health challenge with oral diseases estimated to be the most prevalent condition in the world.1 Untreated dental caries (tooth decay) of the deciduous teeth affects 8% of the global child population, with greatest prevalence in those under 5 years of age.2 In Scotland, at the beginning of the 21st century, dental caries in 5 year olds was among the worst in Europe, with 60% affected, wide inequalities identified and no improvement observed in the previous decade.3

A 2002 Scottish Government consultation resulted in fluoridation of the public water supply being ruled out,4 5 but with a realisation that a traditional health education approach for oral health improvement was both ineffective and could potentially widen inequalities.6 The resultant national oral health strategy established demonstration pilot projects which developed into the national child oral health improvement programme—Childsmile.7 The Childsmile programme is described in detail elsewhere8—briefly, it is a multicomponent preventive programme operating at upstream (policy), midstream (community) and downstream (clinical) levels. It follows a proportionate universal approach—delivering both universal interventions to all children and additional targeted interventions focused on children predicted to be at higher risk of dental caries from the most socioeconomically deprived backgrounds, with the twin aims of improving child oral health and reducing associated inequalities in the population.9 10 Childsmile’s main focus has been on preschool children (aged up to 5 years). The four main interventions of the programme for this age group are (1) dental health support worker (DHSW) home and community contacts (targeted from birth to children and their parents/carers in greatest need as identified by health visitors, for prevention advice, to help facilitate attendance in primary care dental practice, and to link families with community assets); (2) nursery (kindergarten) fluoride varnish applications (FVAs) (targeted to children from the of age 3 years from the more deprived communities, applied twice per year by extended duty dental nurses); (3) primary care dental practice visits (available from birth for all children attending where toothbrushing instruction, diet advice and FVAs are offered); and (4) nursery-supervised toothbrushing (universal to all preschool establishments in Scotland, including daily toothbrushing with fluoride toothpaste and distribution of toothbrush/toothpaste packs for home use). Following piloting, these interventions were collectively rolled out nationally from 2010/2011.

A monitoring and evaluation strategy for the Childsmile programme was developed based on recommended approaches for the evaluation of complex interventions.11 A theory-based approach to evaluation, incorporating a logic model, guided the development of studies to gather process and outcome measures. The evaluation plan included an ecological evaluation of nursery-supervised toothbrushing,12 13 an embedded randomised controlled trial of nursery fluoride varnish14 and an individual child-level data linkage study using the emerging NHS Scotland infrastructure (this present study).15

Several Cochrane reviews show effectiveness of the fluoride-based interventions16 17; however, the evidence in relation to the proportionate universal delivery of combinations of these interventions at the population level is untested. Here, we developed a cohort using data linkage methods of routine administrative data to assess the reach of the Childsmile programme (with its universal and targeted interventions) by area-based socioeconomic deprivation and to undertake an analysis of the impact of the Childsmile interventions on dental caries outcomes among Primary 1 children (age range 4–6 years old) in 2014/2015 in Scotland (the first cohort of children to be born into the nationally rolled-out programme) by the overall population and then by area-based socioeconomic deprivation…

*Original study in full text online at https://bmjopen.bmj.com/content/10/11/e038116

**Read the full study online in pdf format, http://fluoridealert.org/wp-content/uploads/kidd-2020.childsmile-wsuppl.pdf