Transferring decision-making on the fluoridation of drinking-water from local authorities to district health boards

This regulatory impact statement was developed to inform policy decisions on whether to transfer decision-making on the fluoridation of drinking-water supplies from territorial local authorities in order to improve oral health outcomes and reduce disparities between groups and communities.

The practice of fluoridation in New Zealand is based on the advice of the World Health Organization and other international health authorities. The case for extending fluoridation is based on a number of studies, including those published by the Cochrane Collaboration, and the Prime Minister’s Chief Science Advisor and the Royal Society of New Zealand. The latter comments on ‘the compelling evidence that fluoridation of water at the established and recommended levels produces broad benefits for the dental health of New Zealanders’.

The case for extending fluoridation is also based on cost-effectiveness studies published by J. C. Wright et al (1999), the National Fluoride Information Service (2012) and the Sapere Research Group (2015). There is consistent evidence that the fluoridation of water-supplies for populations of more than 1000 people is cost-effective (ie, the savings resulting from fluoridation exceed the costs). The Sapere report estimates that extending water fluoridation to those areas that are currently unfluoridated would be associated with net savings of over $600 million over 20 years, with most of the savings to consumers and a small amount to Vote Health. The conclusion that fluoridation and extended fluoridation would result in net savings was shown to be robust under a range of assumptions.

Sapere was not able to clearly isolate the incremental operating costs of adding fluoridation systems from general plant operations. It has estimated the annual costs of fluoridation for plants of various sizes, based on costing information from 17 water treatment plants.

The Ministry of Health has considered a range of options for managing fluoridation and increasing the proportion of the population having access to fluoridated water supplies. It concluded that the DHB option represents a significant advance on the current arrangements through territorial local authorities and could achieve the potential health gains that have been identified. The proposed regulatory framework would support DHBs and it would ensure that the process is more robust than it is at present. The Ministry also notes that the risk of legal challenge would remain, but that this is a feature of the status quo.

This analysis was conducted in light of the Government’s commitment to improvements in oral health, outlined in its strategic vision for oral health in New Zealand.

Back to top