Comparison of urban and rural mortality rates across the lifespan in Aotearoa/New Zealand: a population-level study
Garry Nixon, Gabrielle Davie, Jesse Whitehead, Rory Miller, Brandon de Graaf, Ross Lawrenson, Michelle M. Smith, John Wakerman, John Humphreys, Sue Crengle
Abstract
BACKGROUND: Previous studies undertaken in New Zealand using generic rurality classifications have concluded that life expectancy and age-standardised mortality rates are similar for urban and rural populations. METHODS: Administrative mortality (2014-2018) and census data (2013 and 2018) were used to estimate age-stratified sex-adjusted mortality rate ratios (aMRRs) for a range of mortality outcomes across the rural-urban spectrum (using major urban centres as the reference) for the total population and separately for Māori and non-Māori. Rural was defined according to the recently developed Geographic Classification for Health. RESULTS: Mortality rates were higher overall in rural areas. This was most pronounced in the youngest age group (<30 years) in the most remote communities (eg, all-cause, amenable and injury-related aMRRs (95% CIs) were 2.1 (1.7 to 2.6), 2.5 (1.9 to 3.2) and 3.0 (2.3 to 3.9) respectively. The rural:urban differences attenuated markedly with increasing age; for some outcomes in those aged 75 years or more, estimated aMRRs were <1.0. Similar patterns were observed for Māori and non-Māori. CONCLUSION: This is the first time that a consistent pattern of higher mortality rates for rural populations has been observed in New Zealand. A purpose-built urban-rural classification and age stratification were important factors in unmasking these disparities.