A GIS-based spatial equity assessment framework : measuring potential accessibility and assessing spatial equity of healthcare services integrating size and quality for social groups at the household level on the city scale: a case study of GP practices in the UK

Abstract

This research intends to develop a more comprehensive and accurate GIS-based Spatial Equity Assessment Framework. The purpose is to provide guidance for measuring potential accessibility integrating size and assessing spatial equity integrating quality for social groups at the household level on the city scale. The research reviews the existing studies in planning and health-related fields on disaggregation techniques, potential accessibility and potential access measurement and spatial equity assessment. As the most accurate place access measurement method, the Population Weighted Centroid (PWC) technique suffers from aggregation errors, a cadastral and address-based population weighting technique, the Household Space Weighting (HSW) technique is developed to measure population access. The HSW technique is formally tested in a case study of General Practitioner (GP) surgeries in Newcastle upon Tyne, UK. The findings suggest that the PWC technique produces inaccurate population estimations for 267 out of 910 output areas in the city. When applying the two techniques to measure potential accessibility for social groups, taking into account the overlay of service areas on the city scale, the measurement error for the PWC technique is 9-11%, depending on the social group considered. The relative difference in the percentage of social groups with potential access applying the two techniques is 18-22%. This suggests that if service planners or policy makers want to measure potential access to services for social groups in their cities, it would be useful to apply a more accurate population weighting technique, or to at least be aware of the implications of applying the PWC technique. The research also demonstrates the necessity of incorporating demand apart from equality and need and integrating quality in addition to size into spatial equity assessment framework. Thus, the GIS-based Spatial Equity Assessment Framework that is developed in this research is more comprehensive and accurate than the existing studies. The research summarizes how to apply the assessment framework to provide policy recommendations for cities on the city scale. The assessment framework has potential to extend from measuring potential access and assessing spatial equity of healthcare services to other services and from measuring potential access to realized access.