Several spatial measures of community food access identifying so called "food deserts" have been developed based on geospatial information and commercially-available, secondary data listings of food retail outlets. It is not known how data inaccuracies influence the designation of Census tracts as areas of low access. This study replicated the U.S. Department of Agriculture Economic Research Service (USDA ERS) food desert measure and the Centers for Disease Control and Prevention (CDC) non-healthier food retail tract measure in two secondary data sources (InfoUSA and Dun & Bradstreet) and reference data from an eight-county field census covering 169 Census tracts in South Carolina. For the USDA ERS food deserts measure accuracy statistics for secondary data sources were 94% concordance, 50-65% sensitivity, and 60-64% positive predictive value (PPV). Based on the CDC non-healthier food retail tracts both secondary data demonstrated 88-91% concordance, 80-86% sensitivity and 78-82% PPV. While inaccuracies in secondary data sources used to identify low food access areas may be acceptable for large-scale surveillance, verification with field work is advisable for local community efforts aimed at identifying and improving food access.
Bibliographical noteFunding Information:
This work was supported by a grant from the RIDGE Center for Targeted Studies at the Southern Rural Development Center at Mississippi State University. The food environment data were funded by NIH 1R21CA132133 . The contents of this article are solely the responsibility of the authors and do not necessarily represent the official views of the RIDGE Center for Targeted Studies or the National Cancer Institute or the National Institutes of Health.
- Dun & Bradstreet
- Field census
- Food desert
- Food environment