29 April 2026
Chris Johnston
[FYI request #28619 email]
Tēnā koe Chris
Further response to your request for official information, ref: HNZ00067356
On 2 October 2024, you submitted a request to Health New Zealand | Te Whatu Ora (Health NZ)
seeking the following information:
Please expand on Health NZ’s previous response to OIA HNZ00061156 by
breaking the numbers down into Age Range and number of doses of any COVID vaccine
received by the person at the date/time of arrival at the Emergency Dept.
The response should be in a machine readable format - in a csv or Excel format is
acceptable.
To recap, the original OIA read: ‘ The number of people under the age of 40 presenting to
Emergency departments throughout
NZ hospitals with Chest pain or heart issues for the years 2017 to 2024 ? (Please provide
figures year by year)’
Further breakdown requested in this OIA:
1) Age Ranges - under 40, 40 to 65 inclusive, over 65
2) Doses - 0,1,2,3,4,5,6,7+
3) Where a person had multiple visits to an Emergency Dept in a year please provide two
columns - a total count and a unique count of NHI numbers.
Cell obfuscation:
a) Where a cell is <5 people please populate this with "<5" for confidentiality.
b) True zero cells should be shown - as zero and not marked as <5.
Please do consult as early as possible if there are any issues or questions. This a distinct
OIA from my previous ones as it breaks down another person’s OIA and is in the public’s
interest that it be responded to separately.
This is similar in intensity and effort to previous OIAs for data that Health NZ has
successfully responded to. It may require linking the hospital dataset to the pay per
dose/immunisation database via the NHI Number - or your data warehouses (eg
Snowflake) may have already structured the required dataset - eg for safety monitoring and
alarming.
I understand you were not happy with our decision under the Official Information Act (OIA) of 3
December 2024 to withhold some information, and that you subsequently made a complaint to the
Ombudsman. Health NZ has since reconsidered the release of the information.
Response
Health NZ is unable to provide a breakdown of Emergency Departments (ED) presentations by
COVID-19 vaccination status, as this information is not linked within our IT systems. As a result,
fulfil ing this part of your request would necessitate the creation of new information and is therefore
refused under section 18(g) of the OIA as the information is not held.
Appendix One contains counts of presentations and counts of distinct patients at ED by age of the
patient for calendar year 2018 to 2025 for specific SNOMED codes for Chief Presenting Complaint.
Notes about the data in Appendix One:
- This data includes ED events where the Chief Presenting Complaint SNOMED code
included the phrase “chest pain”.
- We excluded codes that indicate the presentation was not chest pain, for example ‘Chest
pain not present (situation))’, and codes related to muscoloskeletal chest pain issues.
- It does not include information from level 2 ED facilities provided by private institutions.
- It excludes people who Did Not Attend (DNA) or Did Not Wait (DNW).
Please note the following limitations and caveats related to this information:
- As advised in our previous responses to you, Health NZ does not hold the exact data which
you requested.
- The data in Appendix One is incomplete for the years 2018 to 2023. Any apparent
increases in numbers is due to lower rates of reporting in these years, rather than an actual
increase in presentations in later years.
o The apparent large rise over the last six years is a result of incomplete data collection,
not an actual rise in chest pain ED presentations. What appears as a large rise in the
number of ED presentations due to chest pain is a direct result of the way the data was
previously collected, which did not include all Districts.
o Some public hospital emergency departments in New Zealand first began providing
clinical codes for Chief Presenting Complaint and Diagnosis from July 2019. Not all
hospitals began reporting at the same time. Al publicly funded hospitals attached to a
former District Health Board were reporting clinically coded data for Chief Presenting
Complaint from their Emergency Departments by April 2024.
o This means that prior to April 2024, information about why people visited ED is not
complete enough to report on at a national level.
o 2024 and 2025 are the only years that all districts at Health NZ were recording this data
and only a few Districts (between 2 and 4) were recording this data prior to 2020.
Additionally, not all 20 Districts use the same code for recording this data, so the data
set is incomplete.
- We have provided numbers for Chief Presenting Complaint SNOMED codes which contain
the phrase ‘chest pain’, but this wil not capture all events relevant to your query.
o Chief Presenting Complaint information from ED data is coded using SNOMED – an
international clinical coding system. SNOMED is a hierarchical coding system that has
around 125,000 codes for clinical findings and disorders.
o These codes can be used to select all emergency department visits where chest pain
or one of its subtypes has been explicitly recorded, but these may not capture the
events you are interested in. For example, the chest pain related codes do not include
myocardial infarction.
- Chest pain on presentation to ED can be attributable to many conditions, and the initial
reason for presentation often differs from the final diagnosis. The final diagnosis made
when a patient is discharged is the most valuable information when comparing data for a
specific condition (but is not what was asked for).
- Counts between 1 and 4 have been replaced with <5 in accordance with section 9(2)(a) of
the Act to protect the privacy of individuals. Health NZ does not consider that the public
interest outweighs the need to withhold numbers <5.
- This data is provisional - it has not undergone the validation process that we use for
published data. We recommend that caveats are consistently used, underscoring that the
data is provisional, not validated through a formal validation process, and is subject to
change.
As noted in our previous response, the information provided under HNZ00061156 should have
been released with more appropriate context and caveats. Health NZ has apologised for this
oversight and contacted the requester as soon as this was discovered.
How to get in touch
If you have any questions, you can contact us at
[email address].
If you are not happy with this response, you have the right to make a complaint to the
Ombudsman. Information about how to do this is available a
t www.ombudsman.parliament.nz or
by phoning 0800 802 602.
We have also advised the Ombudsman’s office of our further response to you.
Ngā mihi
Sara Freitag Manager, Government Services
TeWhatuOra.govt.nz
Health NZ, PO Box 793,
Wel ington 6140, New Zealand
