The Geographic Classification for Health: Methodology and classification report

Abstract

The GCH is based on population and drive time data that was used in the development of the Urban Accessibility (UA) classification (Statistics New Zealand, 2020). The UA is in turn based on the Statistical Standard for Geographic Areas 2018 (SSGA18) which includes the urban rural 2018 (UR2018) classification (Statistics New Zealand, 2018). The authors of this report have applied a framework to the UA classification that considers a health services discourse to determine appropriate population and drive time thresholds. We have tested both the quantitative and ‘on-the-ground’ validity of the GCH, in partnership with the Ministry of Health’s National Rural Health Advisory Group (NRHAG).

The GCH is comprised of five categories, two urban and three rural, that reflect degrees of reducing urban influence and increasing rurality. The GCH applies these categories to all of New Zealand’s Statistical Area 1s (SA1s, small statistical areas which are the output geography for population data) on a scale from ‘Urban 1’ to ‘Urban 2’ based on population size, and from “Rural 1’ to ‘Rural 3’ based on drive time to their closest major, large, medium, and small* (*As defined in the Statistical Standard for Geographic Areas 2018 (Statistics New Zealand, 2018)) urban areas. Like the UA, the GCH is based on population size and density, with drive time used to indicate increasing rurality. Unlike the UA, which is a generic classification, the population and drive time thresholds used in the GCH have been developed from a health perspective, in consultation with more than 300 individuals from 20 organisations. The nature of the functional relationships between urban areas and rural surrounds have also been considered through a health lens.

In this paper we discuss concepts and issues with previous ‘generic’ urban-rural classifications being used in health research in Aotearoa New Zealand. We also describe the GCH methodology and classification, discuss limitations, and illustrate the GCH with maps.