Is water fluoridation a cost saving intervention for Irish schoolchildren?

Objectives: The burden of dental decay lasts a lifetime as once the tooth structure is impaired it will require restorative treatment along with replacement restorations over the lifetime of the tooth. This cost benefit analysis compares the annual benefit of water fluoridation (CWF), to the annual cost of its supply. Methods: Guided by the methodologies applied in recent economic evaluations of CWF, we calculated the net annual benefit of CWF from the health payer’s perspective using a discount rate of 4% per annum. All costs are reported in 2017 Euros. Scenario and probabilistic sensitivity analysis were performed using a 10,000 iteration Monte Carlo simulation to account for uncertainty in key assumptions and parameters. The averted decay attributable to the CWF intervention was estimated using dental caries outcome data on decayed missing, and filled teeth (D3vcMFT) from a representative sample of 12-year-old school children collected by the FACCT study. The lifetime treatment cost of decay was modelled over a lifetime using the Dental Treatment Services Scheme cross-sectional distribution of treatments. The cost of provision of CWF included capital costs, operating and maintenance costs along with the acid cost. Data obtained from national agencies and reports were used in the estimation of CWF costs for each water treatment plant (WTP). Results: The annual cost averted to the health payer was €17.85 per 12- year-old child. The mean annual cost to supply CWF to the population of Ireland was €2.15 per person. This represents a national saving to the health payer of €722,250 for 12-year-old children (N=45,995) in receipt of fluoridated water from the Irish public water supply for the year 2017. Conclusions: CWF as a health intervention provides a reduction in the national disease burden and offers significant cost-savings to the Irish health-payer.