Accessibility of the Australian population to an ICU, and of ICUS to each other

Objective: To use a geographic information system to qualitatively and quantitatively illustrate the geospatial relationship of the Australian population to intensive care resources. Design, setting and participants: Intensive care unit data were sourced from the Australian and New Zealand Intensive Care Society Centre for Outcome and Resource Evaluation critical care resources survey (2007-2008) and adult patient database (2002-2008), and postcode data (2006) from the Australian Bureau of Statistics. Remoteness was classified within remoteness categories and the Accessibility/Remoteness Index of Australia Plus. Distance was the difference between two postcode's centroids. Results: Ninety-one public ICUs were identified. Of these, 50 (54.9%) were in a major city, 24 (26.4%) were inner regional, 15 (16.5%) were outer regional, one (1.1%) was remote and one (1.1%) was very remote, compared with 64.2%, 20.8%, 11.7%, 1.9% and 1.4% of the population, respectively (P = 0.324). Median population distance to the closest ICU was 35.9 km and closest Level 3 ICU was 54.8 km. This varied by state/territory, ranging from 7.6 km to the closest ICU for the Australian Capital Territory to 161.7 km for Western Australia. Overall, 84.8% of the Australian population were 0-50 km from an ICU, 12.9% were 51-300km, 2.3% were 301-1500 km, and 0.01% were > 1500km. This varied among the states/territories. A Level 3 ICU was the closest ICU for 65.4% of the population, a Level 2 for 27.6% and a Level 1 for 7%. Median distance between any two ICUs was 21.1 km. Generally, the distance between Level 3 ICUs was shorter than the distance to a Level 1 or Level 2 ICU. Conclusions: The distribution of Australian ICUs and the Australian population was similar. However, accessibility varied by state/territory.