133 Molesworth Street
PO Box 5013
Wellington 6140
New Zealand
T+64 4 496 2000
21 April 2026
Alisha Riley
By email: [FYI request #34189 email]
Ref:
H2026080409
Tēnā koe Alisha
Response to your request for official information
Thank you for your request under the Official Information Act 1982 (the Act) to the Ministry of
Health – Manatū Hauora (the Ministry) on 21 March 2026 for information regarding oral health
metrics used in the NZBORA assessment of fluoridation directions. You requested:
“I am writing to request some information under the Official Information Act to help me
better understand the data used in the recent "New Zealand Bil of Rights Act 1990
analysis for 14 fluoridation directions."
On page 10 of Appendix 1, the document states: "New Zealand's Oral Health Survey
shows that, on average, 40% less tooth decay was experienced among children and
adolescents living in communities with fluoridated water..." I am trying to understand how
this 40% relative reduction was translated into actual physical metrics for the Director-
General during the decision-making process. I am interested in the absolute difference
(the Difference in Means) rather than just the relative percentage (the Ratio of Means).
Please note: I am not requesting the raw 2009 New Zealand Oral Health Survey datasets.
My request is strictly for the internal briefing documents, or specific page references within
the decision package, where these absolute metrics were presented.
Could you please provide the following:
1. Information on Absolute Difference (Children):
Any memo, file note, or working document provided to the Director-General during the
drafting of the Memo (or Appendices) that explicitly outlines the absolute Difference in
Means for dmft/DMFT or dmfs/DMFS that corresponds to the 40% relative figure quoted
on page 10.
2. Information on Adult Efficacy:
Please provide the specific internal documents or briefings provided to the Director-
General that show the absolute Difference in Means (for DMFT or DMFS) for the adult
demographic (18+) that was considered when assessing the overall benefit of the policy.
3. Location in the NZBORA Assessment: I have reviewed the publicly available November
2024 decision package (the Memo and all Appendices), but I am unable to locate any
reference to the absolute Difference in Means for dmft/DMFT or dmfs/DMFS. If these
absolute metrics were indeed used to weigh the benefits of the mandate during the s 5
NZBORA assessment, please provide the exact page and paragraph numbers where they
are recorded. If these absolute numbers are not recorded anywhere within the Memo or
its Appendices, please explicitly confirm this omission.”
All information provided to the Director-General of Health in relation to the consideration of
community water fluoridation under the New Zealand Bil of Rights Act 1990 is publicly available
on this page:
www.health.govt.nz/information-releases/director-general-of-health-consideration-
of-community-water-fluoridation-under-the-new-zealand-bill Therefore, section 18(d) of the Act
applies to your request.
If you wish to discuss any aspect of your request with us, including this decision, please feel
free to contact the OIA Services Team on: [email address].
Under section 28(3) of the Act, you have the right to ask the Ombudsman to review any
decisions made under this request. The Ombudsman may be contacted by email at:
[email address] or by calling 0800 802 602.
Please note that this response, with your personal details removed, may be published on the
Ministry website at:
www.health.govt.nz/about-ministry/information-releases/responses-official-
information-act-requests
Nāku noa, nā
Barbara Burt
Acting Group Manager, Public Health Strategy and Policy
Public Health Agency and Mental Health Group
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