In 2006 the National Ethics Advisory Committee, part of the Ministry of Health, issued guidelines for observational studies. It defined the difference between observational studies and intervention studies as follows:

The National Ethics Advisory Committee’s (NEAC) statutory functions are to provide advice to the Minister of Health on ethical issues of national significance regarding health and disability research and services, and to determine nationally consistent ethical standards and provide scrutiny for such research and services.

Ethical Guidelines for Observational Studies, Observational Research, Audits and Related Activities
December 2006
Wellington: Ministry of Health.
This document is available from NEAC’s web site.Foreward, page iii.

“Observational studies are relatively low-risk. There are two main reasons for this. In these studies, the investigators observe and analyse information about health or disability but do not alter the care or services that people receive, and secondly, there is generally a reduced potential for conflict between the investigator role and the clinician role. Observational studies differ from intervention studies, in which investigators intentionally alter people’s care or services to study the safety and benefit of doing so.“Chapter 4, Underlying ethical considerations, states:

“The following considerations are important to the ethics of observational studies.
Respect for people4.2 Respect for people, and for their rights, incorporates at least two fundamental principles:

  1. Autonomy, which requires that people who are capable of deliberation about their personal goals should be treated with respect for their capacity for selfdetermination.
  2. The protection of people with impaired or diminished autonomy, which requires that people who are dependent or vulnerable be afforded security against harm.”

An “intervention study” involves a medical intervention as defined by the European Convention for the Protection of Human Rights and Dignity of the Human Being with Regard to the Application of Biology and Medicine 1997. This is also useful in establishing appropriate standards for intervention, including State intervention, in individual health. Article 5 provides as a general standard:

“An intervention in the health field may only be carried out after the person concerned has given free and informed consent to it. This person shall beforehand be given appropriate information as to the purpose and nature of the intervention as well as on its consequences and risks.”

“Intervention” in this context is defined to include any preventive health measure applied to a human being by any means. It is consequently irrelevant whether added fluorides are “medication” as their use nevertheless constitutes a “medical intervention”.

It should also be noted that fluoride is a medicine as defined in the NZ Medicines Act 1981.

Fluoride Free NZ wrote to the NEAC regarding the Far North fluoridation “trial” as follows:

12 March 2007

Dear Advisory Committee

I write to you in relation to the planned fluoridation trials to be carried out in Kaikohe and Kaitaia. As you may be aware, these have been called “trials” since inception of the idea. Following our indication that we consider such a trial, on a medical matter, to therefore be a medical or scientific experiment in terms of section 10 of the NZ Bill of Rights Act 1990, the Northland District Health Board now claims that this is not really a trial, but merely the collection of statistics; in essence an “observational study” only.

In reading the distinction the NEAC draws between observational and intervention studies in its publication Ethical Guidelines for Observational Studies Observational Research, Audits and Related Activities December 2006, I note that the distinction drawn is that “observational studies differ from intervention studies, in which investigators intentionally alter people’s care or services to study the safety and benefit of doing so”.

In the Far North trial, people’s care or services are clearly being altered, to study the alleged benefit of adding fluoride to their water. This is clearly, to us, an intervention study as defined by the NEAC. We understand that if the water were already fluoridated as a public health measure, and statistics were subsequently collected, this would constitute an “observational study”, however this is not the case here, and appropriate consultation on a proposed public health measure has not been conducted. Neither has this plan ever been proposed on such terms. Such a matter falls, of course, under different considerations in Bill of Rights terms, and has not been addressed since enactment of the Bill of Rights Act. We would therefore be obliged if you could advise your position on this, and what the ethical requirements of this intervention would be. We presume this would include informed consent of every individual, in line with International Conventions.

As this “trial” is due to begin at the end of this month, we would appreciate a response as soon as possible.

We received the following response from the NEAC:

While this acknowledges, importantly, that water fluoridation is an intervention (see discussion above), it avoids the issue put before the NEAC. We wrote back as follows:

7 July 2007.


Thank you for your response of 6 June. The information contained was useful, however did not address the key point of my enquiry. I acknowledge that the committee cannot discuss individual cases, so allow me to phrase a hypothetical question that addresses the point.

First, may we clarify some points from your letter. You acknowledge that fluoridation is an intervention, and note a range of interventions that describe a very broad definition of “intervention”. You will be aware that the 1997 European Convention on Medicine and Human Rights addresses the concept of “medical intervention.” As fluoridation is aimed at effecting a medical result – reduction of dental caries- we would consider fluoridation therefore to be a medical intervention. Although NZ is not a party to the European Convention, is that the NEAC’s interpretation also?

In acknowledging fluoridation per se as an intervention, you also state that it is neither an observational not intervention study in terms of the NEAC’s definition. We would agree: fluoridation is generally applied as a health measure only (whether it is effective and safe or not is not relevant to this enquiry). As such it is not a study of any kind. The situation in the Far North is quite different however. The addition of fluoride has been clearly stated as for the sole purpose of conducting a “study” into its purported effectiveness. By your acknowledgement, fluoridation by nature is an intervention. We acknowledge that if the Far North District Council implemented fluoridation for health reasons this would be a different matter, though still raising the issue of whether any vote of the public can justify a private medical intervention on an individual where the medical condition (dental caries) does not threaten the public health. We acknowledge that this would not be an “intervention study” as it is not a study at all. If the Northland District Health Board subsequently decided to study the effects of that measure, that would then be an “observational study” as the NEAC defines this term. Again, this is not the scenario in the Far North, as stated publicly by the participants. The poll of a (limited) number of residents, on which basis the study proceeded, was whether they agreed to a study; not whether they agreed to fluoridation as a health measure.

To put the matter, then, in general terms, if a chemical substance is added to the water supply, constituting an “intervention” as you acknowledge, and that substance is added for the sole purpose of conducting a trial (study), and a study must be either an observational or interventional study (or is it possible for a study to be other than either an observational study or an intervention study?), it seems from your definition that such a practice must constitute an intervention study, not an observational study. Can you confirm your view on this please.

The NEAC responded as follows:

Fluoride Free NZ responded as follows:

12 March 2008.

Andrew Moore
Chair, NEAC

Dear Mr Moore

Thank you for your letter of 22 November 2007 regarding fluoridation trials. I have to say that I am not only disappointed, but indeed appalled that the Committee is apparently burying its head in the sand and failing to address an ethical question regarding the most controversial public health issue in history.

You have acknowledged that fluoridation is an intervention, as has the Nuffield Council on Bioethics in its 2007 report. You have identified that there are two types of study, “intervention” and “observational”. A trial on individuals to determine medical outcomes by applying an intervention agent specifically for that purpose is, by definition, a study. It seems to me to follow as a matter of logical necessity, therefore, that a fluoridation trial is an “intervention study”.

I am aware that the Committee is part of the Ministry of Health, and that fluoridation is the Ministry’s policy, to a level that can only be described as fanatical. This may make it uncomfortable for the Committee to objectively address the issue, but it is in precisely such situations of State fanaticism that the rights of citizens is at most risk, and the role of the Committee most critical.

In reading the Nuffield report it is clear that the implementation of the Far North trial grossly breaches the standard of ethics discussed by the Council.

It is therefore all the more appalling that the public cannot turn to your Committee to even comment on matters affecting citizens’ rights under section 10 of the NZ Bill of Rights Act 1990, and potentially breaching international standards of bioethics.

I have to ask in all seriousness, if the Committee is prepared to abnegate its responsibilities for any reason, how does it justify its continued existence?

The trial has been in place for almost a year now. Please advise when the Committee might address the issue I have raised.

1. “Report of the Nuffield Council on Bioethics, Public Health: ethical issues”, November 2007.

And here the matter lies as the NEAC has not communicated further, except that we have been advised that the NEAC has for years refused to address the ethics of water fluoridation. Having backed themselves into a corner as above, being funded by the Ministry of Health (which promotes fluoridation zealously), it is not hard to see why.