10 The evidence

Introduction

The evidence statements from 2 reviews and a report are provided by external contractors (see Supporting evidence).

This section lists how the evidence statements and expert papers link to the recommendations and sets out a brief summary of findings from the economic analysis.

How the evidence and expert papers link to the recommendations

The evidence statements are short summaries of evidence, in a review, report or paper (provided by an expert in the topic area). Each statement has a short code indicating which document the evidence has come from.

Evidence statement 1.1 indicates that the linked statement is numbered 1 in review 1. Evidence statement 2.1 indicates that the linked statement is numbered 1 in review 2. Evidence statement ER 1 indicates that the linked statement is numbered 1 in the expert report 1. EP 1 indicates that expert paper 1 is linked to a recommendation.

Where a recommendation is not directly taken from the evidence statements, but is inferred from the evidence, this is indicated by IDE (inference derived from the evidence).

Recommendation 1: evidence statements ER 1.1, ER 1.2, ER 1.5; EP 1

Recommendation 2: evidence statements ER 1.2, ER 1.3, ER 1.4, ER 1.6; EP 1; EP 2

Recommendation 3: evidence statements ER 1.6

Recommendation 4: evidence statements ER 1.1, ER 1.2, ER 1.4; EP 1

Recommendation 5: EP 2

Recommendation 6: evidence statements 2.1, 2.2, 2.9a, 2.9b, 2.11b, 2.12a, 2.12b; EP 1; EP 2

Recommendation 7: evidence statements 1.6; 2.3, 2.4, 2.5, 2.6, 2.9c; EP 1; EP 2

Recommendation 8: evidence statements 1.21, 1.22; 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9b, 2.10, 2.11a, 2.12a, 2.16; EP 1

Recommendation 9: evidence statements 2.3, 2.4, 2.5, 2.6, 2.9c, 2.10, 2.11a, 2.12a, 2.13, 2.14, 2.16; EP 1

Recommendation 10: evidence statements 1.20, 1.21, 1.22; 2.3, 2.4, 2.5, 2.6, 2.8, 2.9c, 2.10, 2.11a, 2.12a; EP 1

Recommendation 11: evidence statements 1.21, 1.22; 2.3, 2.4, 2.5, 2.6, 2.9c, 2.10, 2.11a, 2.12a; EP 1

Recommendation 12: evidence statements 1.6, 1.19; 2.3, 2.4, 2.5, 2.6., 2.7, 2.11a, 2.11b, 2.12b, 2.16; EP 2

Recommendation 13: evidence statements 1.3, 1.4, 1.5, 1.6; 2.3, 2.4, 2.5, 2.6, 2.7, 2.11a, 2.11b, 2.12a, 2.12b, 2.16; EP 2

Recommendation 14: evidence statements 1.3, 1.4, 1.5, 1.19, 1.22, 1.24, 1.25; 2.3, 2.4, 2.5, 2.6, 2.9a, 2.11a, 2.12a, 2.12b; EP 2

Recommendation 15: evidence statements1.2, 1.4, 1.25; 2.9a, 2.9b, 2.9c, 2.11b, 2.12b; EP 2

Recommendation 16: evidence statements 1.2, 1.4,1.8, 1.14, 1.24, 1.25; 2.9a, 2.9b, 2.9c, 2.11b, 2.12a, 2.12b, 2.16; EP 2

Recommendation 17: evidence statements 1.13, 1.14, 1.16, 1.18, 1.25; 2.7, 2.8, 2.11b, 2.12a, 2.12b; EP 2

Recommendation 18: evidence statements 1.12, 1.13, 1.14, 1.15, 1.16, 1.18, 1.19; 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9c, 2.11b, 2.12a, 2.12b, 2.13; EP 2

Recommendation 19: evidence statements 1.11; 2.9a, 2.9b, 2.9c, 2.11a, 2.11b, 2.12a, 2.12b, 2.13; EP 2

Recommendation 20: evidence statements 1.8, 1.14, 1.24; 2.9a, 2.9b, 2.9c, 2.11b, 2.16; EP 2

Recommendation 21: evidence statements 1.8, 1.11, 1.14, 1.16, 1.18, 1.24; 2.5, 2.6; EP 2

Cost effectiveness

Review of economic evaluations

The searches returned 4162 unique records. Sixty-three papers were included after title and abstract screening, with 61 retrieved. After applying the eligibility criteria 17 papers were included and 16 were judged partially applicable.

Two of the 16 studies were judged to have minor methodological limitations, (++), 11 to have potentially serious limitations (+) and 3 to have very serious limitations (−). No study adopted the appropriate perspective for public health studies.

Economic modelling

Originally the economic model was going to assess the cost effectiveness of interventions identified in review 1. The main oral health outcomes to be included were oral cancer, periodontal disease and dental caries. However, due to a paucity of evidence on the first 2 outcomes, the model focused on the effect of interventions on dental caries.

Once built, it became apparent that there were not enough data to input into the model and that expressing the results as single incremental cost effectiveness ratio (ICER) would be of limited value. Instead the model was used to undertake 2 analyses.

The first used additional datasets provided by Public Health England to estimate the risk of poor oral health. It focused on supervised tooth brushing and fluoride varnish programmes in a deprived community of pre-school and school children.

Utilities from studies of otitis media were used as a proxy for the quality of life associated with tooth loss in children. Some members of the PHAC suggested that otitis media, an infection of the middle ear, may reflect the short-term impact of tooth loss. (For example, in terms of the pain, disruption to quality of life, the need for professional care and, in some cases, a surgical intervention.)

The second analysis used sensitivity analyses to explore the uncertainty around the 5 key input parameters:

  • intervention costs

  • baseline risk of dental caries

  • intervention effectiveness (measured as a reduction in relative risk for dental caries)

  • loss in quality-adjusted life years (QALYs) from each incidence of dental caries

  • cost of treating each one.

The values used for each input are shown below:

  • intervention cost per person: £20, £40, £60, £80 and £100

  • baseline risk of dental caries: 10%, 20% and 50%

  • intervention effectiveness: 0%, 10%, 20%, 30% and 40%

  • QALY loss from dental caries: −0.025, −0.05 and −0.1

  • cost of treating dental caries: £75, £100 and £125.

Of the 5 inputs, only the cost of treating dental caries did not appear to have a significant impact on the results. In terms of the QALY loss, the greater the QALY loss, the more likely the intervention would be cost effective. Similarly, cheaper or more effective interventions appeared to be more cost effective. For example, interventions costing £20 per person were much more likely to be cost effective compared to those costing £100 per person. Similarly, those that reduce the risk of caries by say 40% were much more likely to be cost effective than those that reduce it by 10%.

The model concluded that to be cost effective, the total cost per child (not per child per year) of a fluoride varnish or supervised tooth brushing service needs to be less than around £40. If it costs more than £60 per child it is less likely to be cost effective.

The modelling also showed that these interventions are likely to be most cost effective among children from deprived groups who have a higher risk of caries.

The specific scenarios considered and the full results can be found in RX058: Economic analysis of oral health improvement programmes and interventions.

Fieldwork findings

Fieldwork aimed to test the relevance, usefulness and feasibility of putting the recommendations into practice. The PHAC considered the findings when developing the final recommendations. For details, go to Fieldwork and Field testing NICE guideline on oral health: local authority oral health improvement strategies.

Fieldwork participants who commission and provide services linked to the promotion of oral health for local populations and groups at high risk of oral health were positive about the recommendations. Many stated that the guideline would focus attention and resources on what is an important area of public health.

Many participants also welcomed supervised tooth brushing schemes and fluoride varnish programmes for identified groups. Some expressed a concern that the emphasis on such interventions could potentially undermine the need to encourage self-reliance: that is, to encourage people to develop the skills and habits they need to ensure their own oral health. Some also felt it was unclear whether some interventions were more important than others (especially supervised tooth brushing schemes compared with fluoride varnish programmes).

Participants wanted further details on what could be done to address the needs of adults at high risk of poor oral health and more on the training of frontline staff.

Some terminology in the draft guideline was confusing. For example, use of the term 'low in sugar' alongside 'sugar-free', and it was unclear what differentiated 'higher risk' and 'very high risk' groups. In addition, participants said it was unclear how the guideline would be implemented. They noted the importance of ensuring the recommendations reflect how local authorities plan and deliver oral health promotion activities in the 'real world' to assist implementation.

Overall, practitioners and commissioners said that the recommendations did not offer a new approach, but agreed that the measures had not been implemented universally. They believed more systematic implementation would be achieved if there was information about the relative effectiveness and cost-effectiveness of supervised tooth brushing schemes and fluoride varnish programmes versus other options.

  • National Institute for Health and Care Excellence (NICE)