Mortality Collection

The Mortality Collection was established to provide data on causes of death for New Zealand’s vital statistics, for public health research, policy formulation, monitoring the effectiveness of health programmes, and 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.

The Mortality Collection classifies the underlying cause of death for all deaths registered in New Zealand and all registered fetal deaths (stillbirths). New Zealand is currently using the ICD-10-AM classification and the WHO 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.

Deaths registered in New Zealand from 1988 onwards 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.

For further details refer to the Mortality Collection Data Dictionary.

Each month Births, Deaths, and Marriages (BDM) sends Health New Zealand – Te Whatu Ora electronic death registration 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, and coroners’ reports supplied by the Coronial Services Unit.

Additional information on underlying cause of death is obtained from hospital discharge data in the National Minimum Dataset (NMDS), the New Zealand Cancer Registry (NZCR), the NZ Transport Agency, Water Safety NZ, the Internet, and from 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 National Collections, Health New Zealand staff for maintenance, data quality, audit and analytical purposes.

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

Health New Zealand is required to ensure that the release of information recognises any legislation related to the privacy of health information, in particular the Official Information Act 1982, the Privacy Act 2020 and the 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 three annual web tools:

• Mortality data web tool
• Suicide data web tool
• Fetal and infant deaths data web tool

The latter publication contains detailed information on numbers and rates of live births, fetal deaths, and neonatal and post-neonatal deaths.

Customised datasets or summary reports are available on request from data-enquiries@health.govt.nz. Staff from this Data Services team can help to define the specifications for a request and are familiar with the strengths and weaknesses of the data.

The Data Services team also offers a peer review service to ensure that national collections’ data is reported appropriately when published by other organisations.

There may be charges associated with data extracts.