Kia ora Alisha,

  

Thank you for your request under the Official Information Act 1982 (the
Act), received by the Ministry of Health - Manatū Hauora on 22 March 2026.
You requested:
 

"1. The Statistical Formula: 
Please provide the specific mathematical formula, weighting, or protocol
used to correct the 2022 Community Oral Health Service data for the
"unequal provision of dental services" and "uneven geographic
distribution" admitted to in Footnote 3 (page 3, Appendix 1).

2. Confirmation of Non-Adjustment: 
If no mathematical weighting or demographic corrections were applied to
this "unreliable" clinic-attendance sample before it was used to justify a
Section 5 NZBORA human rights breach, please confirm this in writing.

3. Reliability Briefings: 
Please provide all internal memos, risk assessments, or briefings provided
to the Director-General discussing the "unreliability" of the 2022
dataset.

4. The Accepted Margin of Error: 
Please provide the specific "margin of error" the Ministry accepted when
using this clinic-attendance sample to calculate the "proportionality"  of
the 14 directions.

5. Broken Evidentiary Link: 
Footnote 3 (page 3) directs the reader to a specific Discussion on the
Limitations of the Data at
[1]https://aus01.safelinks.protection.outlo...
This link is currently broken and returns a "404 Error." Please provide
the full, original document that was intended to be reached by that link
at the time the Director-General signed the November 2024 analysis."

We have noted your additional queries pertaining to the Community water
fluoridation: New Zealand Bill of Rights analysis and will be providing a
response under reference number H2026080414. You can expect a response by
21 April 2026, being 20 working days after the day your request was
received. If we are unable to respond to your request by then, we will
notify you of an extension of that timeframe.

 

If you have any queries regarding your request, please feel free to
contact the OIA Services Team on [2][email address]. If any
additional factors come to light which are relevant to your request,
please do not hesitate to contact us so that these can be taken into
account. 

 

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: [3][email address] or by calling 0800
802 602.

 

 

Ngā mihi, 
 
OIA Services Team

Ministry of Health | Manatū Hauora

 

M[4]inistry of Health information releases

 

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References

Visible links
1. https://www.ehinz.ac.nz/assets/Reports/O...
2. mailto:[email address]
mailto:[email address]
3. mailto:[email address]
mailto:[email address]
4. https://www.health.govt.nz/about-ministr...
https://www.health.govt.nz/about-ministr...

Kia ora Alisha
Please find attached the response to your request for official
information. 
Ngā mihi

OIA Services Team

Ministry of Health | Manatū Hauora

show quoted sections

Kia ora Alisha,
  
Thank you for your request under the Official Information Act 1982 (the
Act), received by the Ministry of Health - Manatû Hauora on 22 April 2026.
You requested:
 

"Thank you for the corrected link to the EHINZ report. Having reviewed the
documentation the Ministry relies upon, I require urgent clarification
regarding your refusal to provide the specific technical and internal data
requested under Section 18(d) of the Act. Please reply by 27 April, 2026.

 

If the Ministry is claiming that all information provided to the
Director-General (DG) is contained within the public links (
www.health.govt.nz/information-
releases/director-general-of-health-consideration-of-community-water-fluoridation-under-the-new-zealand-bill
  AND
 ehinz.ac.nz/indicators/water/drinking-water-quality/oral-health-of-children/
), please provide the specific page and paragraph numbers for the
following, or alternatively, provide the internal documents requested:

 

1. The Use of Unadjusted Data :
The provided Metadata
(https://aus01.safelinks.protection.outlo...)
explicitly states that for the COHS data, "Reliable comparisons... is not
possible without adjusting for a number of demographic variables which are
not recorded in the source data". Furthermore, the EHINZ perspective notes
the data are "raw data, unadjusted".

 

Request:
Please provide the specific internal memo, email, or briefing document
acknowledging that the DG was advised/warned regarding the use of this
unadjusted data for the Nov 2024 analysis, or provide the specific
mathematical formula the Ministry held to override/compensate this
limitation (and its exact location in the public links).

 

2. The "Policy Development" Warning:
The EHINZ report explicitly states that "the national statistics from the
COHS do not accurately portray the oral health status... and cannot be
used in decision-making or policy development".

 

Request:
Please provide any internal briefing, risk assessment, or correspondence
where the Ministry addressed this specific warning prior to using this
"unsuitable" dataset to justify the 14 fluoridation directions.

 

3. The "Dampening Effect" Omission (Regarding Caries Data):
The EHINZ report clarifies that the "narrowing gap" in caries-free health
status is a "dampening effect" caused specifically by the Auckland region,
warning that the national trend is "unduly influenced" by a single region
and does not accurately portray the oral health status of fluoridated
versus non-fluoridated areas.

 

Request: Please provide the internal briefing or working document where
the DG was informed or where the DG discussed that the national COHS
dataset used to calculate the "proportionality" of the 14 directions was,
according to your own source, an inaccurate portrayal of national trends.

 

4. The Fluorosis Data Exclusions & "Not Increasing" Metric:
In my March 21 request (Questions 2-5), I asked for internal memos
detailing how safety was assessed for the 0–7 and 31+ demographics, given
the 2009 Oral Health Survey restricted fluorosis data to ages 8–30.

I also requested the longitudinal comparative dataset used to legally
conclude on page 13 that fluorosis is "not increasing." You refused these
under s18(d). The provided links do not contain discussion of  these age
exclusions, nor does it contain a comparative longitudinal dataset to
justify the "not increasing" claim.

 

Request:
Please provide the specific page and paragraph numbers within the public
links where these specific discussion and the comparative longitudinal
dataset can be found. If they are not in the public link, s18(d) is
incorrect, and I request the documents be released or the omissions
explicitly confirmed as originally requested."
 

The reference number for your request is H2026081951. We will endeavour to
respond to your request as soon as possible and in any event no later than
21 May 2026 being 20 working days after the day your request was received.
If we are unable to respond to your request by then, we will notify you of
an extension of that timeframe.
 
If you have any queries regarding your request, please feel free to
contact the OIA Services Team on [1][email address]. If any
additional factors come to light which are relevant to your request,
please do not hesitate to contact us so that these can be taken into
account. 
 
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: [2][email address] or by calling 0800
802 602.
 
 
Ngâ mihi, 
 
OIA Services Team
Ministry of Health | Manatû Hauora

 
M[3]inistry of Health information releases
 
 
 

--------------------------------------------------------------------------

From: Alisha Riley <[FOI #34198 email]>
Sent: Wednesday, 22 April 2026 15:50
To: OIA Requests <[email address]>
Subject: Re: Response to your official information Act request, ref:
H2026080414 CRM:0001232
 
Subject:
Clarification of Refusal H2026080414 – Inappropriate use of s18(d) &
Request for Internal Documents

Attention:
OIA Services Team / Barbara Burt

Hi,

Thank you for the corrected link to the EHINZ report. Having reviewed the
documentation the Ministry relies upon, I require urgent clarification
regarding your refusal to provide the specific technical and internal data
requested under Section 18(d) of the Act. Please reply by 27 April, 2026.

If the Ministry is claiming that all information provided to the
Director-General (DG) is contained within the public links (
[4]www.health.govt.nz/information-
releases/director-general-of-health-consideration-of-community-water-fluoridation-under-the-
new-zealand-bill   AND 
ehinz.ac.nz/indicators/water/drinking-water-quality/oral-health-of-children/
), please provide the specific page and paragraph numbers for the
following, or alternatively, provide the internal documents requested:

1. The Use of Unadjusted Data :
The provided Metadata
([5]https://aus01.safelinks.protection.outlo...)
explicitly states that for the COHS data, "Reliable comparisons... is not
possible without adjusting for a number of demographic variables which are
not recorded in the source data". Furthermore, the EHINZ perspective notes
the data are "raw data, unadjusted".

Request:
Please provide the specific internal memo, email, or briefing document
acknowledging that the DG was advised/warned regarding the use of this
unadjusted data for the Nov 2024 analysis, or provide the specific
mathematical formula the Ministry held to override/compensate this
limitation (and its exact location in the public links).

2. The "Policy Development" Warning:
The EHINZ report explicitly states that "the national statistics from the
COHS do not accurately portray the oral health status... and cannot be
used in decision-making or policy development".

Request:
Please provide any internal briefing, risk assessment, or correspondence
where the Ministry addressed this specific warning prior to using this
"unsuitable" dataset to justify the 14 fluoridation directions.

3. The "Dampening Effect" Omission (Regarding Caries Data):
The EHINZ report clarifies that the "narrowing gap" in caries-free health
status is a "dampening effect" caused specifically by the Auckland region,
warning that the national trend is "unduly influenced" by a single region
and does not accurately portray the oral health status of fluoridated
versus non-fluoridated areas.

Request: Please provide the internal briefing or working document where
the DG was informed or where the DG discussed that the national COHS
dataset used to calculate the "proportionality" of the 14 directions was,
according to your own source, an inaccurate portrayal of national trends.

4. The Fluorosis Data Exclusions & "Not Increasing" Metric:
In my March 21 request (Questions 2-5), I asked for internal memos
detailing how safety was assessed for the 0–7 and 31+ demographics, given
the 2009 Oral Health Survey restricted fluorosis data to ages 8–30.
I also requested the longitudinal comparative dataset used to legally
conclude on page 13 that fluorosis is "not increasing." You refused these
under s18(d). The provided links do not contain discussion of  these age
exclusions, nor does it contain a comparative longitudinal dataset to
justify the "not increasing" claim.

Request:
Please provide the specific page and paragraph numbers within the public
links where these specific discussion and the comparative longitudinal
dataset can be found. If they are not in the public link, s18(d) is
incorrect, and I request the documents be released or the omissions
explicitly confirmed as originally requested.

Alisha Riley

show quoted sections

Kia ora Alisha

 

Please find attached the response to your request for official
information. 

 

Ngā mihi,

 

 

OIA Services Team

Ministry of Health | Manatū Hauora

 

show quoted sections