Analysing geographic variation in lower urgency emergency department presentations using readily – available administrative boundaries and a novel spatial smoothing technique. Issue 2 (3rd April 2022)

• Record Type: Journal Article
• Authors: Kok, Mei Ruu; Tuson, Matthew; Turlach, Berwin; Boruff, Bryan; Vickery, Alistair; Whyatt, David
• Is Part Of: Australian geographer. Volume 53:Issue 2(2022)
• Page Start: 223
• Page End: 235
• Publication Date: 2022-04-03
• Subjects: Lower urgency ED presentations -- geographic variation -- spatial aggregation -- modifiable areal unit problem -- smoothing -- Overlay Aggregation Method; Geography -- Periodicals; Australia -- Description and travel -- Periodicals; 910
• DOI: 10.1080/00049182.2022.2059825
• Languages: English
• ISSNs: 0004-9182

Abstract

ABSTRACT: Misallocation of finite healthcare resources can occur when guided by maps that are produced using aggregate-level administrative units. Such maps are affected by the modifiable areal unit problem (MAUP), which describes how patterns may change depending on the particular choice of mapping unit. Smoothing can help avoid this unintended yet detrimental phenomenon. This paper compares the utility of aggregate-level administrative units and smoothing for exploring variation in lower urgency emergency department (ED) presentations across metropolitan Perth, Western Australia. Rates of such presentations were mapped using Australian Bureau of Statistics Statistical Areas Levels 1, 2, and 3 (SA1-3s) and the recently proposed Overlay Aggregation Method (OAM). Resulting maps were compared based on their ability to represent local variation in rates and optimise the targeting and logistical efficiency of geographically targeted resource allocation. SA1-level variation in rates was increasingly obscured by SA2s and SA3s. OAM helped avoid this pitfall, facilitating stable identification of SA1-resolution, high-rate regions while preserving privacy, mitigating the MAUP, and balancing the targeting and logistical efficiency of planned resource allocation to those regions. Routine application of smoothing can help avoid issues undermining maps of lower urgency ED presentations and other health outcomes that are based on aggregate-level administrative units.