16 January 2026
Elspeth Baker-Vevers
[FYI request #33051 email]
Tēnā koe Elspeth
Official Information Act (OIA) request: Collection of ADHD data
On 29 November 2025, you requested information regarding the collection of ADHD data.
I have considered your request under the Official Information Act 1982 (the Act). For ease of
reference, I will respond to each part of your request in turn.
1. Current Identification Capacity for ADHD in IDI Please outline which diagnosis
codes, pharmaceutical indicators, education flags, benefit/ACC/justice variables,
disability support datasets, or other IDI variables currently exist that would enable
accredited researchers to identify ADHD or probable ADHD cohorts.
o
If ADHD cannot presently be identified in this way, please confirm this and
note any known limitations.
4. Classification and Metadata
o
If ADHD is not represented as a standalone category within underlying
datasets, please confirm how related information is coded (e.g., mental
health, neurodevelopmental, behavioural, disability, pharmaceutical).
o
Please also provide:
metadata references
the relevant IDI Data Dictionary links or extracts showing where ADHD
related fields, codes, or pharmaceutical indicators appear (or do not
appear)
If any Māori data governance, Māori statistical standards, or Māori
equity considerations were applied when determining how ADHD
related information is categorised or represented in classification
systems, please provide the relevant documents.
The
Household Disability Survey 2023 asked about ADHD diagnosis information, which has
been ingested into the IDI. While there will be additional methods of identifying ADHD data
in the IDI, it is important to note that Stats NZ are stewards of the IDI and not experts on
specific datasets themselves and would not be best placed to assess whether variables con
be used to confirm an ADHD diagnosis. A more accurate answer would come from data
suppliers themselves.
[email address]
toll-free 0508 525 525
stats.govt.nz
8 Willis Street, Wellington
PO Box 2922, Wellington 6140
While Stats NZ cannot speak to Māori data governance, Māori statistical standards, or Māori
equity considerations being applied when determining how ADHD related information is
categorised or represented in classification systems, you may be interested in the Ngā
Tikanga Paihere framework more generally.
Ngā Tikanga Paihere is a framework intended to help researchers identify potential impacts
of their research and engage with Māori and other communities to ensure the use of
microdata is respectful, ethical, and culturally appropriate.
While this framework was designed based on Māori concepts, it is applied more broadly to
guide consideration of risks and benefits and appropriate consultation with a range of
communities in New Zealand. These might include minority ethnic groups, people with
disabilities, retirees and any other group that may be affected by the publication of outputs
using their data.
The framework is available
here. Stats NZ also has information on how to apply Ngā Tikanga
Paihere to research projects
here.
2. Research Activity and System Awareness The 2025 University of Otago study
demonstrated that ADHD cohorts can be identified in IDI datasets and linked to cross-
sector outcomes.
o
Please provide:
o
Any records (2015–present) showing whether ADHD specific analyses using
the IDI have been:
proposed
approved
undertaken
commissioned or requested by an agency
carried out by external researchers (e.g., Otago, AUT, or other
accredited IDI researchers)
o
Any records discussing Stats NZ awareness of, or engagement with, the 2025
Otago research.
o
If no such documents are held, please confirm this.
We understand that the research you refer to relates to an IDI project titled
Neurodevelopmental impairment in the Justice Sector. A summary of the project is available
here.
As with all applications submitted to use the IDI, the researchers undertook a rigorous
application process designed to ensure data is used safely, ethically, and for public good.
A proposal was submitted outlining the research purpose, public value, and how the IDI
data will be used. This project was assessed against the Five Safes framework, including
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people, project, settings, data, and outputs. Applicants were approved as safe researchers
and agreed to strict confidentiality and privacy obligations.
Once approved, access was provided in a secure Data Lab environment, with all outputs
checked before release to ensure individuals or groups cannot be identified.
There are no records of additional active or completed projects in the IDI specific to ADHD.
3. Pipeline, Prioritisation, and Approval Please provide any documents or advice
outlining:
o
how agency commissioned IDI research topics (including
neurodevelopmental research) are approved or prioritised -criteria or
thresholds governing feasibility assessments -the process for agencies to
request or fund commissioned IDI analyses
When it comes to approving applications to use microdata for research, Stats NZ does not
prioritise Government agency research above any other type of application. The same
approval process applies to all applicants, and is publicly available here:
Apply to use
microdata for research | Stats NZ.
5. Rainbow+/Takatāpui populations
o
Please provide any analysis, metadata, or available information regarding
whether ADHD related outcomes can be examined for Rainbow+/Takatāpui
populations in the IDI, or confirm if such data are not col ected or not linkable
for this purpose.
o
How, if at al , did the 2013 Census changes relating to sex and gender
categories affect the ability to analyse any overlaps between ADHD (or other
neurodevelopmental conditions) and Rainbow+/Takatāpui populations in the
IDI or in census-linked datasets?
o
Please describe whether internal Stats NZ teams responsible for
Rainbow+/Takatāpui populations, disability statistics, and health statistics
col aborate to understand intersectional data needs or gaps relevant to ADHD
and other neurodevelopmental conditions.
Disability and LGBTIQ+ data subject matter experts at Stats NZ have worked together to
produce insights for the disabled rainbow population through the 2023 Household Disability
Survey. This was the first time disability statistics had been available for the LGBTIQ+
population, following the collection of LGBTIQ+ data in the 2023 Census.
The 2023 Census was the first to collect gender and included an option for people to
indicate another gender different to male or female. Older censuses collected a person's
sex rather than their gender, using only male and female categories.
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While the 2023 Census did not collect data on ADHD and other neurodevelopmental
conditions, analysis did show higher activity limitations for LGBTIQ+ populations. In
particular, LGBTIQ+ populations had higher proportions of difficulty remembering and
concentrating that the non-LGBTIQ+ population (see
LGBTIQ+ population of Aotearoa New
Zealand: 2023, chapter 3). This was the first time the 2023 Census was able to produce
activity limitation data for LGBTIQ+ communities, and it provided a valuable first step in
identifying areas of further data need in official statistics.
At present, the internal teams responsible for rainbow populations, disability statistics and
health do not have a formal collaboration mechanism in place, to jointly explore
intersectional data needs or gaps relating to ADHD or other neurodevelopmental conditions.
Data related to neurodevelopmental conditions from the 2023 Household Disability Survey
is limited to people aged 5 years and over who have been diagnosed with ADHD and/or
autism. Stats NZ do not hold comprehensive data on the broader neurodevelopmental
population, including those without a formal diagnosis or those younger than five.
Stats NZ also collect information on gender and have produced estimates of ADHD prevalence
disaggregated by gender. However, due to smal sample sizes, Stats NZ are only able to report
on male and female categories.
Going forward, Stats NZ will ensure that the new census model delivers value for priority
communities, including LGBTIQ+ and disabled communities. Stats NZ intend to establish
collaborative community design groups to help to achieve this, and intersectionality
between these communities will be a focus for this work. More information is available
here.
6. Feasibility or Costing Information
o
Any indicative costing guidance, pricing schedules, or feasibility notes relating
to commissioning an equivalent IDI analysis focused on ADHD or other
neurodevelopmental conditions.
o
If Stats NZ does not produce such costing guidance, please confirm.
Stats NZ charge the fol owing fees to cover costs for access to microdata in the Data Lab:
• Assess and approve application: $500 + GST (fee is waived for government
applications, no charge for unsuccessful applications).
• Storage: 200GB cap. Over cap $1.50 + GST per GB per month.
These details are also publicly available here
: Apply to use microdata for research | Stats NZ.
We also offer customised data services that has access to the IDI to produce data outputs with
a standard charge of $155 plus GST per hour. More information on this service can be found here:
Customised data services | Stats NZ
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7. Gaps /Non-col ection
o
If Stats NZ does not hold some or al of the information requested, this
absence also helps clarify how ADHD is currently tracked and managed
across systems.
o
Please confirm if any information is not held, and include any records that
document:
decisions not to col ect ADHD related variables
data limitations affecting ADHD visibility
constraints on classification or linkage
We do not hold any records documenting decisions not to collect ADHD related variables or
limitations relating to ADHD in relation to collecting ADHD diagnosis information as part of
the 2023 Household Disability Survey. As such, this part of your request is refused under
section 18(e) of the Act as this information does not exist or, despite reasonable efforts to
locate it, cannot be found.
Should you wish to discuss this response with us, please feel free to contact Stats NZ at:
[email address].
If you are not satisfied with this response, you have the right to seek an investigation and
review by the Ombudsman. Information about how to make a complaint is available at
www.ombudsman.parliament.nz or 0800 802 602.
It is Stats NZ’s policy to proactively release its responses to official information requests
where possible. This letter, with your personal details removed, will be published on the Stats
NZ website. Publishing responses creates greater openness and transparency of government
decision-making and helps better inform public understanding of the reasons for decisions.
Nāku noa, nā
Fau Logo
Senior Manager – External & Government Relations
Office of the Chief Executive | Tari o te Kaitatauranga Matua me te Pouārahi Matua
Stats NZ | Tatauranga Aotearoa
stats.govt.nz
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