Comparing GIS-Based Methods of Measuring Spatial Accessibility to Health Services
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The inequitable geographic distribution of health care resources has long been recognized as a problem in the United States. Traditional measures, such as a simple ratio of supply to demand in an area or distance to the closest provider, are easy measures for spatial accessibility. However the former one does not consider interactions between patients and providers across administrative borders and the latter does not account for the demand side, that is, the competition for the supply. With advancements in GIS, however, better measures of geographic accessibility, variants of a gravity model, have been applied. Among them are (1) a two-step floating catchment area (2SFCA) method and (2) a kernel density (KD) method. This microscopic study compared these two GIS-based measures of accessibility in our case study of dialysis service centers in Chicago. Our comparison study found a significant mismatch of the accessibility ratios between the two methods. Overall, the 2SFCA method produced better accessibility ratios. There is room for further improvement of the 2SFCA method—varying the radius of service area according to the type of provider or the type of neighborhood and determining the appropriate weight equation form—still warrant further study.
KeywordsSpatial accessibility GIS Floating catchment Kernel density
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- 7.Radke J, Mu L (2000) Spatial decomposition, modeling and mapping service regions to predict access to social programs. Geogr. Inform Sci 6:105–112Google Scholar
- 9.Center for Health Statistics, (2002) Inventory of Health Care Facilities and Services and Need Determinations, Hospitals and Associated Services, vol. 1, Parts I-V., Illinois Department of Public Health, IllinoisGoogle Scholar
- 10.US Bureau of Census (2000) Census Summary File 1Google Scholar
- 11.Apparicio P, Shearmur R, Brochu M, Dussault G (2003) The measure of distance in a social science policy context: Advantages and costs of using network distances in eight Canadian Metropolitan areas. J Geogr Inform Decision Anal 7(2):105–131Google Scholar
- 12.Wang F (2005) Measuring distances and time. In Wang F, Albert DP, Albrecht J (eds.) Quantitative Methods and Applications in GIS, Chap. 2, CRC Press, Boca Raton, FLGoogle Scholar
- 13.Guagliardo MF (2004) Spatial accessibility of primary care: Concepts, methods and challenges. Int J Health Geogr 3(3):1–13Google Scholar
- 14.Wang F (2005) GIS-based measures of spatial accessibility and application in examining health care access. In Wang F, Albert DP, Albrecht J (eds.) Quantitative Methods and Applications in GIS, Chap. 5, CRC Press, Boca Raton, FLGoogle Scholar
- 15.Guptill SC (1975) The spatial availability of physicians. Proc Assoc Am Geogr 7:80–84Google Scholar
- 16.United States General Accounting Office (2004) Medicare dialysis facilities: Beneficiary access table and problems in payment system being addressed, JuneGoogle Scholar