By Ken Perrott 28/01/2016


A new report on the cost effectiveness of community water fluoridation (CWF) confirms it is still effective.

The report is:

Ran, T., & Chattopadhyay, S. K. (2016). Economic Evaluation of Community Water Fluoridation: A Community Guide Systematic Review. American Journal of Preventive Medicine.

This study is a systematic review of the literature.  A total of 564 papers were identified, but after excluding studies which didn’t fit the inclusion criteria, this was whittled down to ten studies (8 peer-reviewed journal articles and 2 reports) published in the period 2001 – 2013. The studies were located in Australia, USA, Canada and New Zealand.

Intervention costs

The review found:

“Per capita annual cost ranged from $0.11 to $4.92 in 2013 U.S. dollars for communities with  >1,000 population. The variation in per capita annual cost was mainly attributable to community population size. Specifically,
per capita annual cost decreased as population size increased, after adjusting for factors such as discount rate.”

And

“per capita annual cost was the highest when population size was around 1,000. As community population size increased, per capita annual cost decreased. In particular, per capita annual cost for communities with >20,000 population was <$1.”

Intervention benefits

The caries reduction reported in the reviewed studies ranged from 15 – 33%.per capita annual benefits ranged

Intervention benefits included averted healthcare costs and productivity losses. The per capita annual benefits reported in these studies ranged from $5.49 to $93.19

Benefit-cost ratios

As would be expected the reported benefit-cost ratios varied with population size – ranging from 1.12 to 57.21.

So, the authors’ conclusion was:

“In summary, benefit–cost ratios were larger than 1.0 for communities of at least 1,000 people, indicating that CWF was cost beneficial for communities with no fewer than 1,000 people.”

Possible issues

The authors list a number of issues for consideration in future studies of this issue. Interestingly these include two that anti-fluoride campaigners argue have been ignored:

Cost of fluorosis: The authors say this should be included “if there is clear evidence of severe dental fluorosis.”

The only study to have included such costs is that of Ko & Theissen (2014). They included costs of repair or severe dental fluorosis – despite there being no evidence that CWF causes either moderate or severe dental fluorosis. Ko and Theissen made no attmept to justify inclusion of this cost and the “mistake” is not doubt due to the well-known anti-fluoride sympathies of Theissen (see Alternative reality of anti-fluoride “science” for a discussion of this paper).

Political costs: The authors give as an example “expenses associated with promoting CWF.”

Of course, this would also include the legal and referendum costs we have seen imposed on New Zealand local bodies over the last few years. But it should also include the private costs of those who campaign for and against CWF and the larger corporate costs of bodies like the NZ Health Trust which has initiated unsuccessful High Court action. The NZ health trust is a lobby group for the “natural”/alternative health industry and their costs no doubt eventually get passed on to the consumers of their products and services.

It would be interesting to see the breakdown of such political costs for different countries and regions. I imagine it would be hard to predict what these costs could be in an individual situation. Although I can appreciate local bodies may feel obliged to budget for such costs.

And I wonder if one should include the cost of legal justice and democratic consultation in a cost-benefit analysis. This could lead to people questioning parliamentary elections or their rights to challenge corporations and criminals in the courts.

Should anti-fluoride campaigners do their own cost-benefit analysis?

It’s a simple fact that anti-fluoride campaigners lose more of their struggles than they win – even in the USA. It’s also a fact that they see the threat of imposition of legal and consultation costs as a way of pressuring local bodies to avoid the issue. But, I wonder if they have ever undertaken a cost-benefit analysis on their own activities.

For example, given the failures of the High Court action by the campaigners over recent years and the lack of success in referenda held in New Zealand in 2013 and 2015 perhaps they should do a few “back of the envelope” calculations.

If they want to personally enjoy drinking water that is “fluoride free” then what is the most reliable intervention they could apply to achieve that benefit.

Consider two scenarios:

1: A political approach. The costs of referendum and consultation campaigns, their personal loss of income and free time in making submissions, organising Paul Connett’s Southern hemisphere holiday tours of New Zealand and Australia. Consider also the costs to the “natural”/alternative health industry in their taking and sponsoring legal actions.  Balance this against the very low likelihood of success – and possibly also consider the negative result of social criticism and discrediting that may represent a financial loss to those who run businesses or are practitioners in the “natural”/alternative health industry.

2: A personal responsibility approach. The cost of  purchasing a relatively cheap and effective water filter to lower the F concentration in their tap water. The capital cost would be a few hundred dollars per household and the annual costs would not be large. In fact, the NZ Health trust may help lower these costs by reinvesting the money they would otherwise lose in paying for unsuccessful court actions. The benefits would be immediate and clear. They would get the “fluoride free” water they have demanded. They would have a lot more free time to devote to their families and businesses. And they would not get the current condemnation they get from local body politicians and voters who resent the increased costs their actions have caused in the past.