Cost-Effectiveness of Applying Fluoride Varnish to Preschoolers in a Brazilian Scenario: An Economic Modelling Study

International economic evaluations have not found convincing evidence that the application of fluoride varnish (FV) in preschool children is a cost-effective anti-caries measure, and there is a lack of economic evaluations of FV in the Brazilian context.

This study evaluated the cost-effectiveness (CE) of standard care plus FV for Brazilian preschoolers in the general population, comparing it to standard care in terms of prevention of cavitated caries lesions and disability-adjusted life years (DALY) outcomes.

Markov models were used, with a 4-year time horizon and 6-month cycles. Transition probabilities were obtained from a national epidemiological survey and randomised controlled trials (RCTs). The effectiveness of FV was derived from a systematic review of RCTs. Costs (in Brazilian reais) were sourced from the 2022 National Agency for Supplemental Health dental procedures list. A discount rate of 5% was applied. CE analyses, Markov simulations (MS), and sensitivity analyses (SA) were conducted. Deterministic sensitivity analysis (DSA) used a 95% confidence interval for each variable. For probabilistic sensitivity analysis (PSA), beta distribution curves were used for probabilities, gamma for costs, and lognormal for effectiveness.

Standard care plus FV showed an increase in effectiveness (0.01894 and 0.00018 for avoided caries and DALY, respectively) compared to standard care, with an additional cost of R$131.27 per child in the 4-year period. The ICER (incremental cost-effectiveness ratio) was calculated at R$6929.09 per cavitated caries lesion prevented and R$727604.84 per DALY avoided. MS revealed little difference in the percentage of individuals in each health state at the end of the simulations. FV prevented cavities in 4 out of every 100 children over a 4-year period, at an average annual cost of R$33 per child (assuming each child who developed cavitated caries lesions had only one). DSA indicated that FV effectiveness was the parameter with the highest potential to influence the ICER. PSA suggested high CE thresholds, from which FV would be considered cost-effective: R$7000 for caries and R$730000 for DALY.

The total cost of care was lower in the group that invested less in prevention (without FV) compared to the group that invested more (with FV). While it is often said that "more prevention is always better," economic evaluations remind us that not all preventive strategies provide good value for money.