Custo-benefício da fluoretação da água de abastecimento público

BELOTTI, L. Cost-benefit analysis of community water fluoridation. Thesis School of Public Health University of São Paulo, 2022. OBJECTIVE: To analyze potential factors associated to the quality of fluoridation of public water supply, its cost-effectiveness and cost-effectiveness in different population sizes and age groups in Brazil. METHOD: An economic evaluation study was carried out, in which both resource consumption and health benefits were measured. Initially, an ecological study was carried out to evaluate factors associated with the quality of fluoridation, using Poisson regression. A case study was carried out to analyze the costs of fluoridation, and data referring to the costs of initial installation, chemical product, system operationalization and control of fluoride levels were considered. To analyze the effectiveness of fluoridation, a systematic review was carried out with Brazilian studies comparing the experience of caries in fluoridated and non-fluoridated areas. The economic evaluation was conducted from the perspective of society, cost-effectiveness and cost-benefit were calculated, and direct and indirect costs of procedures that could be avoided were included, with a discount rate of 3.5%. Sensitivity analysis was performed to assess the robustness of the results. RESULTS: The factors associated with the quality of fluoridation were population size of the municipality, compliance with chlorine concentration, per capita income, and type of sanitation company. The annual per capita cost of fluoridation ranged from US$ 7.32 for municipalities with less than 2 thousand inhabitants to US$ 0.14 for municipalities with approximately 520 thousand inhabitants. In systems that serve up to 30 thousand inhabitants, the cost of operation was responsible for most of the expenses, ranging from 98.2 to 84%. In the size of 520 thousand inhabitants, the costs with the chemical product corresponded to 74.7% of the expenses. The mean difference in dmft between fluoridated and nonfluoridated areas was -2.28 (95%CI -3.26; -1.30) for children aged 5 to 8 years and 1.12 (95%CI -1.93; -0.32) for 3 to 12 years. The mean difference in DMFT was -0.61 (95%CI -0.80; -0.42) and caries prevalence was 1.4 times and 57% lower in primary and permanent dentition, respectively. Avoided costs from fluoridation were US$174.40 and US$85.67 for children aged 5-8 and 3-12 years, respectively, and US$46.66 for children aged 7-12 years. The cost-effectiveness and cost-benefit results were favorable in all scenarios where the population size served was 6,000 or more inhabitants. Unfavorable scenarios were observed only in size up to 2,000 inhabitants. CONCLUSION: Fluoridation remains a low-cost per capita and effective measure against dental caries even with the widespread use of fluoride toothpaste. In addition, it is economically advantageous mainly in more populated areas, both in deciduous and permanent dentition. As the decision-making process in the field of public policies is complex and decision-makers suffer multiple influences around different policy alternatives, knowing the factors related to the quality of fluoridation, its costs and its effectiveness is essential for an informed decision making. Key-words: Fluoridation; water supply; cost-analysis; meta-analysis; health economics.