Lead author and University of Otago School of Medicine rural health associate dean Prof Garry Nixon said the study was the first to show a consistent pattern of higher mortality rates and poorer health outcomes for rural populations.
"We believe this study is more accurate than others.
"It uses recent data, it uses a definition of ‘rural’ that was developed with health in mind and validated for that purpose and, importantly, it considers each age group separately."
The research used the newly developed five-level Geographical Classification for Health and population and drive-time thresholds to classify all of New Zealand’s land area into five categories — two urban and three rural — ranked from most rural to most urban, he said.
Using Ministry of Health and Statistics New Zealand mortality data, the study analysed the age, sex and ethnicity of 160,179 people and the cause of their deaths between 2014 and 2018.
Deaths were categorised into five outcomes — all-cause, amenable (those that are potentially avoidable if given effective and timely healthcare), cardiovascular, cancer and injury.
Mortality rates were higher in rural areas than in major urban areas across all groups aged under 60, Prof Nixon said.
The largest disparities were most apparent among those aged under 30 in the most rural communities, where the mortality rates were double those in the most urban centres — 599 deaths in urban areas per 100,000 compared with 1085 in rural areas.
He said the disparities were most evident for injury and amenable death, but still present for cardiovascular disease.
For cancer deaths, the disparities were overall smaller and evident in only some age categories.
Co-author and University of Otago Ngāi Tahu Māori Health Research Unit researcher Prof Sue Crengle said rurality compounded the already high Māori mortality rate.
The all-case age standardised mortality rate for Māori living in the most rural areas was 4018 per 100,000 compared with 3055 per 100,000 for non-Māori.
Prof Crengle said the reasons for the disparities were not analysed in the study, but they were likely to be "multiple and complex", and it was not yet understood how many of these disparities could be accounted for by socioeconomic factors.
"This has important health policy implications in a country where rural health outcomes have been assumed to be as good, if not better, than those in urban areas.
"Because amenable mortality is an indicator for the coverage and quality of healthcare, the presence of rural-urban disparities in this category has implications for the delivery of equitable healthcare to rural population."
She said the new data should not necessarily be viewed as negative.
The results would help inform the Rural Health Strategy being developed by Te Whatu Ora Health New Zealand and Te Aka Whai Ora.
