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Updated: Jun 10, 2026
04:46
'Boden Food Plate': Novel Interactive Web-based Method for the Assessment of Dietary Intake
Published on: September 18, 2018
An evaluation of edge effects in nutritional accessibility and availability measures: a simulation study.
Emily M Van Meter1, Andrew B Lawson, Natalie Colabianchi
1Division of Biostatistics and Epidemiology, College of Medicine, Medical University of South Carolina, Charleston, SC, USA. EmilyVanMeter@gmail.com
International Journal of Health Geographics
|July 29, 2010
Summary
Edge effects bias accessibility measures in geographic studies. Simulations show corrections are needed for accurate spatial analysis of food outlets and restaurants.
Area of Science:
- Spatial analysis
- Geographic information systems (GIS)
- Public health research
Background:
- Accessibility and availability indices are crucial for understanding food environments.
- Study boundaries can significantly influence these spatial measures.
- Outlet density, including food retail and restaurants, is a key factor.
Purpose of the Study:
- To evaluate the statistical use of accessibility and availability indices.
- To investigate the impact of study boundaries (edge effects) on these measures.
- To assess bias introduced by edge censoring in spatial analysis.
Main Methods:
- Extensive simulation using cluster outlet models.
- Comparison of measures within a large study window versus an internal subset.
- Scenarios included urban (2000 outlets) and non-urban (300 outlets) settings.
Main Results:
- Considerable bias observed at study region edges, especially for accessibility measures.
- Edge effects were smaller for non-smoothed availability measures.
- Short-range accessibility measures exhibited fewer edge effects.
Conclusions:
- Studies using accessibility/availability indices must correct for edge effects.
- Guard areas are recommended for edge correction.
- Avoidance of large-range, distance-based accessibility measures is advised.
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