Deaths by suicide in New Zealand

The New Zealand Social Deprivation Index is a measure of socioeconomic status calculated for small geographic areas. It is calculated at the level of meshblocks (geographical units containing a median of 90 people), and the Ministry of Health maps these to domicile codes, which are built up to the relevant geographic scale using weighted average 'usually resident population' counts from the Census. This publication presents suicide death rates by deprivation quintile of residence, ranging from 1 (least deprived) to 5 (most deprived), according to the 2013 New Zealand Deprivation Index. Approximately equal numbers of people reside in areas associated with each of the five deprivation areas.

Rates are not calculated where a category has fewer than five suicide deaths. Calculating rates of suicide from fewer than five suicide deaths produces unstable rates.
People with unknown deprivation quintile are excluded.

Suicide: In New Zealand, a death is only officially classified as suicide by the coroner on completion of the coroner’s inquiry. In some cases, an inquest may be heard several years after the death, particularly if there are factors relating to the death that need to be investigated first (for example, a death in custody). Consequently, a provisional suicide classification may be made before the coroner reaches a verdict.

The number of suicide deaths refers to the number of people who have died by suicide.
The number of suicide deaths in this dataset differs from the number released by the Chief Coroner. The Chief Coroner’s data includes all deaths initially identified at the coroner’s office as self-inflicted. However, only those deaths determined as ‘intentionally self-inflicted’ after investigation will receive a final verdict of suicide. Some deaths provisionally coded as suicide may be determined not to be suicide at a later date. In addition, when coroners do not specify whether self-inflicted poisoning is accidental or with intent to harm, the coding rules require the death would be coded to accidental poisoning (not undetermined intent). This rule could lead to an overstatement of accidental poisonings and an understatement of deaths from undetermined intent.
The Ministry reports on those deaths determined to be suicide after a completed coronial process or those provisionally coded as intentionally self-inflicted deaths before the final coroner’s verdict. Furthermore, the Chief Coroner’s data relates to years ending 30 June rather than the calendar years used in this report.

Rates are expressed per 100,000 population. A rate measures how often a suicide occurs relative the number of people in the population, or a subset of the population.
An age-standardised rate is a rate that has been adjusted to take account of differences in the age distribution of the population over time or between different groups (for example, different ethnic groups). The standard population used is the WHO World Population.
The rate ratio refers to the frequency with which these events are reported in one population group compared with other groups.

Caution is advised when interpreting rates derived from small numbers as they may fluctuate markedly over time. This may apply to both small numbers of cases and/or small population groups.

At URL provided, select 'Suicide Facts: Data tables 1996-2015' from the box to the right-hand side of the page.

These tables present data about suicide deaths in New Zealand over the 20-year period from 1996 to 2015. The tables include numbers and rates by common demographic breakdowns, such as age, sex, ethnicity, district health board (DHB) of residence, neighbourhood deprivation.

The purpose of this report is to present numbers, trends and demographic profiles of people who die by suicide or seriously harm themselves. Understanding this data is important for policy makers, clinicians and others who work to prevent suicide and intentional self-harm.

All New Zealand suicide data in these tables was extracted from the Ministry of Health’s Mortality Collection (MORT) on 13 February 2018. The data for other Organisation for Economic Co-operation and Development (OECD) countries was sourced from the OECD.