Comparing GIS-based methods of measuring spatial accessibility to health services

Area of Science:

• Health Services Research
• Geographic Information Systems (GIS)
• Spatial Analysis

Background:

• Healthcare resource distribution is inequitably spread geographically in the US.
• Traditional spatial accessibility measures have limitations in capturing complex provider-patient interactions and demand-side competition.
• Geographic Information Systems (GIS) offer advanced methods for assessing spatial accessibility.

Purpose of the Study:

• To compare the effectiveness of two GIS-based spatial accessibility measures: the two-step floating catchment area (2SFCA) method and the kernel density (KD) method.
• To evaluate these methods using a case study of dialysis service centers in Chicago.
• To identify potential improvements for GIS-based accessibility measures.

Main Methods:

• Employed GIS to analyze spatial accessibility of healthcare resources.
• Applied the two-step floating catchment area (2SFCA) method.
• Applied the kernel density (KD) method.
• Conducted a comparative analysis using dialysis service centers in Chicago as a case study.

Main Results:

• A significant mismatch was observed between the accessibility ratios generated by the 2SFCA and KD methods.
• The two-step floating catchment area (2SFCA) method generally produced more accurate accessibility ratios.
• The study highlighted discrepancies in spatial accessibility assessments based on the chosen GIS method.

Conclusions:

• The two-step floating catchment area (2SFCA) method is a more effective tool for measuring spatial healthcare accessibility compared to the kernel density (KD) method.
• Further research is needed to refine the 2SFCA method, including adjusting service area radii and optimizing weight equation forms.
• Improved spatial accessibility measures are crucial for addressing healthcare resource disparities.