A cost-effectiveness analysis of community water fluoridation for schoolchildren.

BACKGROUND: Community water fluoridation (CWF), the controlled addition of fluoride to the water supply for the prevention of dental caries (tooth decay), is considered a safe and effective public health intervention. The Republic of Ireland (Ireland) is the only country in Europe with a legislative mandate for the fluoridation of the public water supply, a key component of its oral health policy. However, more recently, there has been an increase in public concern around the relevance of the intervention given the current environment of multiple fluoride sources and a reported increase in the prevalence of enamel fluorosis. The aim of this economic analysis is to provide evidence to inform policy decisions on whether the continued public investment in community water fluoridation remains justified under these altered circumstances. METHODS: Following traditional methods of economic evaluation and using epidemiological data from a representative sample of 5-, 8-, and 12-year-old schoolchildren, this cost-effectiveness analysis, conducted from the health-payer perspective, compared the incremental costs and consequences associated with the CWF intervention to no intervention for schoolchildren living in Ireland in 2017. A probabilistic model was developed to simulate the potential lifetime treatment savings associated with the schoolchildren's exposure to the intervention for one year. RESULTS: In 2017, approximately 71% of people living in Ireland had access to a publicly provided fluoridated water supply at an average per capita cost to the state of euro2.15. The total cost of CWF provision to 5-, 8-, and 12-year-old schoolchildren (n = 148,910) was estimated at euro320,664, and the incremental cost per decayed, missing, or filled tooth (d(3vc)mft/D(3vc)MFT) prevented was calculated at euro14.09. The potential annual lifetime treatment savings associated with caries prevented for this cohort was estimated at euro2.95 million. When the potential treatment savings were included in the analysis, the incremental cost per d(3vc)mft/D(3vc)MFT prevented was -euro115.67, representing a cost-saving to the health-payer and a positive return on investment. The results of the analysis were robust to both deterministic and probability sensitivity analyses. CONCLUSION: Despite current access to numerous fluoride sources and a reported increase in the prevalence of enamel fluorosis, CWF remains a cost-effective public health intervention for Irish schoolchildren.