Rurality, Deprivation and Ethnicity in New Zealand: Population Distributions and Intersecting Impacts on Mortality

OBJECTIVE: To understand how rurality and socioeconomic deprivation intersect to influence health outcomes for Māori (Indigenous population) and non-Māori in Aotearoa New Zealand (NZ). METHODS: Firstly, Census 2018 was used to describe population-level distributions of NZ's 4.7 million residents by rurality [measured using the Geographic Classification for Health (GCH)], socioeconomic deprivation [using NZ's Deprivation Index (NZDep)], and ethnicity (Māori and non-Māori). Secondly, using the national Mortality Collection as the numerator and Census-based population estimates as the denominator, rural: urban mortality rate ratios (MRRs) for Māori and non-Māori, adjusted for NZDep, were estimated from multivariate Poisson regression models. RESULTS: For the NZ population, rurality and socioeconomic deprivation were found to intersect differently for Māori and non-Māori. Of the 160 170 all-cause deaths in 2014-2018, 64% were 75 years or older. Almost half (46%) of the deaths in those under 75 years were considered amenable. For Māori and non-Māori aged 45-59 years, higher rates of mortality (all-cause and amenable) for rural residents, compared to urban, were attenuated when adjusted for socioeconomic deprivation. In those under 45 years, rural: urban disparities in mortality (all-cause and amenable) remained; for example, for Māori the crude amenable MRR was 1.31 (95% CI 1.17, 1.47) and the adjusted, 1.26 (95% CI 1.13, 1.41); for non-Māori, the respective estimates were 1.45 (95% CI 1.33, 1.58) and 1.46 (95% CI 1.33, 1.59). CONCLUSIONS: Māori ethnicity, living in rural areas and socioeconomic deprivation frequently co-exist. Rural-urban disparities in all-cause and amenable mortality evident in younger age groups, particularly those under 45 years of age, cannot be explained by ethnicity or socioeconomic deprivation.