19 May 2023
K Thompson
[FYI request #22572 email] Tēnā koe,
Official information request HNZ00017493
Thank you for your email on 8 May 2023, asking for the following which has been considered
under the Official Information Act 1982 (the Act). Please see outlined below a response to
your request.
Please can you inform us how it was determined that 29 people in New Zealand had died of
Covid (delta variant) in 2020, 2021 and early 2022, as was reported in May 2022, instead of
the earlier reported 52 deaths from Covid (as was reported for example in March 2022).
Was this over-counting of Covid delta deaths due to wrong diagnosis, and, if so, how was
this misdiagnosis determined after the deaths had occurred, at a later date (circa May
2022)? Presumably the over-counting of Covid deaths could not be determined by
autopsy?
The apparent anomaly you are seeing is the result of data upgrades carried out in 2022 and
explained in full below.
Reporting on COVID-19 deaths has many complexities and limitations. Over the course of the
pandemic, the main metric tracking COVID-19 deaths has shifted from deaths ‘with COVID-19’ to
deaths ‘from COVID-19’.
In the early days of the pandemic, COVID-19 death reporting was based on an individual’s death
that occurred within 28 days of a positive case being uploaded. This equates to the measure
‘deaths with COVID-19’. This is a metric that was easy to calculate from data that was readily
available at the time (positive test date and death date).
Developing a ‘deaths from COVID-19’ metric required substantial time and work. Cause of death is
coded by a specialised team within Te Whatu Ora/Health NZ, usually at a significant time lag after
the event of the death. COVID-19 deaths have been fast-tracked for coding where possible, and a
project was stood up to link COVID case data with cause of death data.
Completed in mid-2022, this project enabled us to identify whether COVID-19 played a role in the
death of a person, or whether their COVID-19 infection was purely incidental. Deaths of people
‘with COVID-19’ are now assigned into one of 4 categories.
1. COVID-19 as underlying
2. COVID-19 as contributory
3. Not COVID-19 (i.e. the person had COVID-19 at the time of death, but it didn’t contribute to their
death)
4. Not available
The ‘COVID-19 as underlying’ and ‘COVID-19 as contributory’ categories are often combined into
a single total, which we label interchangeably as ‘COVID-19 attributed deaths’ or ‘deaths from
COVID-19’. This metric provides a better il ustration of the impact of COVID-19 on New Zealand
than the original ‘deaths within 28 days of positive test’ metric original y reported. Consequently,
the move to reporting ‘deaths from COVID-19’ is the reason by the figures on the website dropped
between the dates listed in your question.
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 at
www.ombudsman.parliament.nz or
by phoning 0800 802 602.
As this information may be of interest to other members of the public, Te Whatu Ora may
proactively release a copy of this response on our website. All requester data, including your name
and contact details, will be removed prior to release.
Nāku iti noa, nā
Daniel Hirst
Acting Director
Intelligence Directorate, National Public Health Service
