New Zealand Subnational Abridged Period Life Tables 2022–2024

Method used for the 2022–2024 subnational abridged period life tables: The 2022-2024 subnational abridged period life tables are published along with the national complete period life tables, using statistical model introduced from 2017–2019 life tables. The statistical model was developed to estimate the death rate for age intervals (0, 1–4, 5–9,...,90+) by sex for subnational populations. The release includes subnational life tables for the 2022–2024 period, with a measure of uncertainty (credible intervals) for each of the life table functions, with the median as well as 95 percent limits. The true value of the death rate will be within the 2.5th and 97.5th percentiles, 95 percent of the time, given the input data and the assumed statistical model. For example we can say that 95 percent of the time life expectancy at birth for a male in Northland will be between 78.3 and 79 years, based on the 2022–2024 period life tables. The Arriaga method is used to construct the abridged life tables. Changes to health boundaries Life tables are now published for the new Health Districts introduced in 2023, which supersede the previous district health board (DHB) areas. While most DHB areas remain the same within the health district boundaries, Capital and Coast DHB and Hutt Valley DHB were combined into Capital, Coast and Hutt Health District. To keep time series impact to a minimum, life tables were calculated using DHB areas, and aggregated for Capital, Coast and Hutt Health District using a weighted average based on the population. This method allows for comparability across all districts and time periods as all other boundaries other than Capital, Coast and Hutt Health District have not changed. While the change introduces a discontinuity for Capital, Coast and Hutt Valley Health District, adopting a consistent DHB-level modelling approach ensures methodological stability across the system. Minor differences introduced by the choice of aggregation level are statistically acceptable and do not materially affect interpretation within the bounds of uncertainty. Life table data based on DHB areas are available on request, email [email protected]. Data sources The data used to construct the 2022–2024 subnational life tables comprises: Deaths registered in New Zealand in the December years 2022–2024, respectively, by date of death, date of birth, sex, ethnicity, and geographic area of usual residence. For infant deaths, data provided by Health New Zealand | Te Whatu Ora was used for 2022 and 2023, while Stats NZ deaths by occurrence data was used for 2024. The estimated resident population of New Zealand at 30 June 2018, by age, sex, ethnic group, and geographic area of usual residence. Regional council of usual residence was a variable input to the imputation model for missing ethnicity response (see Ethnicity non-response in deaths data). Death registrations We use death registrations as the numerator to derive the death rates. In 2022–2024, 114,258 deaths were registered in New Zealand, made up of 58,800 male and 55,458 female deaths. The level of non-response to the ethnicity question in death registrations has generally been declining over time. There was no response to the ethnicity question for 386 deaths in 2022–2024 (0.3 percent of all deaths). Death records with missing ethnicity response are imputed using a statistical approach based on records with observed ethnicity response. Read Ethnicity non-response in deaths data below for more information. There are a small number of deaths where the meshblock for the usual residence has been imputed. In 2022–2024, there were 51 deaths (0.04 percent of all deaths) where meshblock was imputed. Population estimates The 2022–2024 subnational life table calculations use, as the population denominator, the estimated resident population at 30 June 2023 – the mid-point of the period. Methodology See New Zealand period life tables: Methodology for 2017–2019 for more detailed methods used to construct the life tables. Comparability of ethnic life tables All ethnic mortality measures should be interpreted with caution because of changes in ethnic concepts and data sources. This includes changes over time as well as differences in measurements between data sources: Read New Zealand Period Life Tables – Significant events impacting this study series for more detailed information on historic changes to the two data collections and other changes. Deprivation index (NZDep2023) The life tables by deprivation area use the New Zealand 2023 index of socio-economic deprivation (NZDep2023). It combines census data relating to income, home ownership, employment, qualifications, family structure, housing, and access to transport and communication, to produce a score for each inhabited Statistical Area 1 and its constituent meshblocks in New Zealand. These scores are grouped into 10 categories (deciles), where 1 represents the areas with the least deprived scores and 10 the areas with the most deprived scores. A value of 10 therefore indicates that an area is in the most deprived 10 percent of areas in New Zealand. More information We produce national abridged period life tables on an annual basis. These are not as detailed as complete life tables, as abridged life tables present functions for grouped ages rather than single years of age, and are not derived by ethnicity. Abridged period life tables are updated annually and will be available in February each year in the Births and Deaths release. See New Zealand Subnational Abridged Period Life Tables in DataInfo+ for more information about life tables, including information about methods. en