Defining rural in Aotearoa New Zealand: a novel geographic classification for health purposes

Abstract

Objectives: To develop a valid rurality classification for health purposes in Aotearoa New Zealand (NZ) that is technically robust and incorporates heuristic understandings of rurality. Setting: Our Geographic Classification for Health (GCH) is developed for all of NZ. Participants: We examine the distribution of the entire NZ population across rurality classifications, and use the National Mortality Collection to examine previously masked rural-urban differences in mortality. Outcome measures: Unadjusted all-cause mortality rates and rural:urban incidence rate ratios (IRRs). Results: The GCH modifies key population and drive time thresholds in the generic rurality classifications, thereby identifying 19% of the NZ population as rural. Rural and urban all-cause mortality rates and associated rural:urban IRRs vary considerably depending on rurality classification. The GCH finds a rural mortality rate 21% higher than for urban areas. Conclusions: The GCH identifies a distinct rural population, and highlights rural-urban inequities that are masked by generic classifications.