Critique of the review of ‘Water fluoridation for the prevention of dental caries’ published by the Cochrane Collaboration in 2024

The Cochrane Review of water fluoridation for the prevention of dental caries published in 2024 has been quoted around the world and has particularly impacted decisions in the USA. The objectives, methods and conclusions have changed little from the Cochrane Review of the same subject published in 2015. The 2015 Review was heavily criticised, since evaluations of public health programmes are seldom amenable to methods such as randomised controlled trials. Using such criteria results in the exclusion of much relevant information. There have been recent advances in methods to evaluate longitudinal and cross-sectional observational studies using ‘causal inference’. The aim of this paper is to consider the merits of the 2024 Cochrane Review in light of advances in evaluating public health programmes and the wider evidence base.