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An assessment of the cost effectiveness of a postal toothpaste programme to prevent caries among five-year-old children in the North West of England |
Davies G M, Worthington H V, Ellwood R P, Blinkhorn A S, Taylor G O, Davies R M, Considine J |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. Health technology The health intervention under scrutiny involved the provision of free toothpaste and toothbrushes to 3-month birth cohorts of children from the age of 12 to 60 months. The toothpaste, containing 1,450 ppm fluoride (F), was posted four times a year for 4 years along with leaflets encouraging twice daily supervised brushing. This intervention was compared with a "do nothing" approach.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised birth cohorts of children aged 12 months living in high caries-risk populations in nine health districts in North West England.
Setting The setting was the community. The economic study was carried out in the UK.
Dates to which data relate The effectiveness data were derived from a paper published in 2002. The price year was not reported.
Source of effectiveness data The effectiveness data were derived from a published study (Davies et al. 2002, see 'Other Publications of Related Interest' below for bibliographic details).
Link between effectiveness and cost data The costing was undertaken retrospectively on the same patient sample as that used in the effectiveness analysis.
Study sample As the main effectiveness study was published elsewhere (Davies et al. 2002), the authors did not report in this paper how the sample size was decided upon, or if power calculations were performed. The names and addresses of eligible children were provided by nine former health authorities in the North West of England, where it was known that caries levels among five-year-olds were high. At the start of the study, 7,422 children were listed, of which 641 indicated they did not wish to take part. Hence, 6,781 children were included in the study. The authors provided no further details on the sample. For more information see the original paper (Davies et al. 2002).
Study design The study was a randomised controlled trial (RCT) that was undertaken throughout homes in the North West of England. The study groups were followed for up to 4 years, and of the 6,781 children who started the study, 5,344 completed it. The authors reported that the exact annual drop-out was not known, but it was assumed that this was distributed evenly between the groups.
Analysis of effectiveness The authors did not report whether the analysis was conducted on an intention to treat basis or on treatment completers only. The outcomes used were:
the mean difference in mean dmft (decayed, missing or filled deciduous teeth surfaces) between the recipients of the intervention and the controls at the time of examination,
the proportion of children suffering caries, and
the proportion of children suffering dental extractions.
At the end of the programme, when the children were 5 to 6 years old, they were examined using the British Association of the Study of Community Dentistry (BASCD) standards. The authors did not report if the study groups were shown to be comparable. For more information see the original paper (Davies et al. 2002).
Effectiveness results The children who received 1,450 ppm F toothpaste had 16% less caries (mean dmft 2.15) than the control group (mean dmft 2.57) who had received no toothpaste. This represented a mean reduction in dmft of 0.42.
The proportion of children who suffered from caries was 50% for the 1,450 ppm F toothpaste group versus 58% for the control group.
Twelve per cent of children in the toothpaste group had experienced one or more dental extractions compared with 17% of the control group.
Clinical conclusions The free toothpaste programme achieved a caries reduction in children receiving the 1,450 ppm F toothpaste.
Measure of benefits used in the economic analysis The measures of health benefits used were the reduction in dmft, child kept free of caries experience, and child kept free of extraction experience.
Direct costs The authors only included the costs of the toothpaste programme and omitted costs such as those related to the treatment of caries. The costs considered were those of establishing and running a postal programme. These were incurred by a salaried dental service and included the labour cost of establishing and running the programme, overheads and product cost. The labour costs were established using the UK NHS Whitley scales for senior dental officers and administrative and clerical scale at grade 4. Agency hourly rates for a database entry clerk and a product packer were used. The overhead costs were established using the mid-point of a range suggested by the Manchester NHS Estates Agency. Discounting was relevant, as the costs were incurred over a 4-year period, and was appropriately performed using a 5% discount rate. The study reported the total costs. The price year was not reported.
Statistical analysis of costs The costs were treated as point estimates (i.e. the data were deterministic).
Indirect Costs The indirect costs were not included.
Sensitivity analysis No sensitivity analyses were performed.
Estimated benefits used in the economic analysis The total dmft reduction associated with the toothpaste programme was 1,846.54 by the end of the intervention.
The authors also estimated that a total of 351.72 children were kept free of caries, and a further 291.83 children did not undergo dental extractions.
Cost results The authors estimated that the total cost of the toothpaste programme over 4 years was 149,264.78, or 27.93 per child.
Synthesis of costs and benefits The authors combined the costs and benefits using an incremental cost-effectiveness ratio (i.e. the additional costs per dmft reduction by one unit, per child kept free of caries experience, or per child kept free of extraction experience). The cost of reducing the dmft by 1 was 80.83, the cost per child kept free of caries was 424.38, and the cost of preventing an extraction experience was 679.01 per child.
Authors' conclusions The programme achieved a significant reduction in caries in children who received the 1,450 ppm fluoride (F) toothpaste. The authors also reported that the costs were now available to those considering the provision of treatment services in areas where children are at high risk of suffering from caries.
CRD COMMENTARY - Selection of comparators An explicit justification for using the do nothing alternative as the comparator was given: the problems of reaching children prior to their commencement of school meant that there was no obvious choice of an alternative approach for comparison. You should decide if this represents current practice in your own setting.
Validity of estimate of measure of effectiveness The analysis was based on an RCT. This was appropriate for the study question as well-conducted RCTs are considered the 'gold' standard when comparing health interventions. The authors provided very few details on the effectiveness study, as this had been published in a separate paper (Davies et al. 2002). It was therefore not possible to comment any further, based on the methods published in this paper.
Validity of estimate of measure of benefit The estimation of benefits was obtained directly from the effectiveness analysis. The authors reported that the benefits may have been underestimated, owing to the short-term period considered in the study and the exclusion of benefits for the children who dropped out.
Validity of estimate of costs The authors reported that the only costs included in the study were those associated with the running and establishment of the toothpaste programme. Therefore, knock-on costs due to the study, such as the costs (or savings) of treatment and extraction of caries, were not included in the analysis. These omissions, as the authors reported, will bias the results against the toothpaste programme. The study costs were appropriately reported by category of cost, making the cost results more transparent, and thus enhancing the generalisability of the study in other settings. The unit costs were derived from published sources. However, the authors did not perform any sensitivity analyses of the costs, either to account for uncertainty or to test the impact of different scenarios on the total cost of the study. Discounting was relevant, as the costs were incurred over a 4-year period, and was appropriately performed. The price year was not reported, which will hamper any possible inflation exercises.
Other issues The authors reported that prior research assessing the cost-effectiveness of dental health promotion programmes had tended to focus on older school-attending children or non-fluoride programmes, and no comparable studies with costings (to permit comparisons) had been found. The issue of generalisability to other settings was not addressed. The authors do not appear to have reported their results selectively and their conclusions reflected the scope of the analysis.
Implications of the study The authors reported that the results of this study would be attractive to those considering a variety of preventive, restorative or surgical means to deal with caries in young children.
Bibliographic details Davies G M, Worthington H V, Ellwood R P, Blinkhorn A S, Taylor G O, Davies R M, Considine J. An assessment of the cost effectiveness of a postal toothpaste programme to prevent caries among five-year-old children in the North West of England. Community Dental Health 2003; 20(4): 207-210 Other publications of related interest Davies GM, Worthington HV, Ellwood RP, et al. A randomised controlled trial of the effectiveness of providing free toothpaste from the age of 12 months on reducing caries in 5-6-year old children. Community Dental Health 2002;19:131-6.
Holland TJ, Considine J, Creedon P. The effectiveness and cost of two fluoride programmes for children. European Journal of Paediatric Dentistry 2001;2:61-6.
Pine CM, McGoldrick PM, Burnside G, et al. An intervention programme to establish regular toothbrushing: understanding parents' beliefs and motivating children. International Dental Journal 2000;50:312-23.
Indexing Status Subject indexing assigned by NLM MeSH Cariostatic Agents /economics; Child, Preschool; Cost-Benefit Analysis; DMF Index; Dental Caries /economics /prevention & England; Fluorides /economics; Humans; Postal Service; Preventive Dentistry /economics /methods; Program Evaluation; Toothpastes /economics; control AccessionNumber 22004006097 Date bibliographic record published 30/11/2005 Date abstract record published 30/11/2005 |
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