Mortality collection

The mortality collection (MORT) classifies the underlying cause of death for all deaths registered in New Zealand and all registered fetal deaths (stillbirths).

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About MORT

MORT combines death registration and stillbirth registration data with cause of death information. This is then collated and coded to create national cause of death statistics.

Scope

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MORT provides data on causes of death for New Zealand’s vital statistics, for:

  • public health research
  • policy formulation
  • monitoring the effectiveness of health programmes
  • cancer survival studies.

A dataset of each year’s mortality data is sent to the World Health Organization to be used in international comparisons of mortality statistics.

For mortality coding, New Zealand currently uses the:

  • ICD-10-AM classification
  • World Health Organization ICD-10 rules and guidelines for mortality coding.

Fetal and infant data is a subset of the mortality collection. Extra variables such as gestation and birth weight are collected for these records.

Using the collection

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Deaths registered in New Zealand from 1988 are held in the mortality database. Data from 1970 to 1987 is also available on request.

The mortality statistics are compiled according to the year the death, or birth for stillbirths, is registered. Causes of deaths for data before 2000 are recorded in ICD-9-CM-A and have not been mapped forward to ICD-10-AM. More details are in the Mortality collection data dictionary.

Mortality collection data dictionary — Data dictionaries

Each month Births, Deaths, and Marriages (BDM) send Health NZ death and stillbirth registration data.  The registration data is matched to Certificates of Causes of Death (HP4720 and HP4721):

  • completed online in death documents or on paper forms sent in by funeral directors
  • coroners’ reports supplied by Coronial Services.

Extra information on underlying cause of death is obtained from:

  • hospital discharge data in the National Minimum Dataset (NMDS)
  • the New Zealand Cancer Registry (NZCR)
  • NZ Transport Agency
  • Water Safety NZ
  • the internet
  • writing letters to certifying doctors and medical records officers in public hospitals.

Electronic files of new death and stillbirth registration data are received fortnightly from BDM.

Electronic data on new notifications of deaths to the coroner and final coroners’ findings are received approximately weekly from Coronial Services.

Electronic and paper Certificates of Cause of Death are received daily.

Manual updates of coded records in MORT are ongoing as new information is received.

The data in the Mortality collection is accessed by authorised Health NZ staff for the purposes of:

  • maintenance
  • data quality
  • audit
  • analytics.

Paper records are stored in a locked office with swipe-card security, and in an offsite secure record storage facility.

We are required to make sure that the release of information meets the conditions of any legislation related to the privacy of health information. In particular the:

  • Official Information Act 1982
  • Privacy Act 2020
  • Health Information Privacy Code 2020.

Information available to the general public is of a statistical and non-identifiable nature. A data release policy covers approval where appropriate from a health ethics committee.

The National collections group publishes 3 annual web tools.

Mortality data web tool

Suicide data web tool

Fetal and infant deaths data web tool

The fetal and infant deaths data web tool contains detailed information on numbers and rates of:

  • live births
  • fetal deaths
  • neonatal and post-neonatal deaths.

Customised datasets or summary reports are available on request. These can be electronic or on paper.

Our team can help to define the specifications for a request and are familiar with the strengths and weaknesses of the data.

We also offer a peer review service to make sure Health NZ data is reported appropriately when published by other organisations.

There may be charges associated with data extracts.

Contact

For more information about this collection or to ask for specific datasets or reports email data-enquiries@health.govt.nz