Many studies examining the food retail environment rely on geographic information system (GIS) databases for location information. The purpose of this study was to validate information provided by two GIS databases, comparing the positional accuracy of food service places within a 1 km circular buffer surrounding 34 schools in Ontario, Canada. A commercial database (InfoCanada) and an online database (Yellow Pages) provided the addresses of food service places. Actual locations were measured using a global positioning system (GPS) device. The InfoCanada and Yellow Pages GIS databases provided the locations for 973 and 675 food service places, respectively. Overall, 749 (77.1%) and 595 (88.2%) of these were located in the field. The online database had a higher proportion of food service places found in the field. The GIS locations of 25% of the food service places were located within approximately 15 m of their actual location, 50% were within 25 m, and 75% were within 50 m. This validation study provided a detailed assessment of errors in the measurement of the location of food service places in the two databases. The location information was more accurate for the online database, however, when matching criteria were more conservative, there were no observed differences in error between the databases.
References
[1]
Papas, M.A.; Alberg, A.J.; Ewing, R.; Helzlsouer, K.J.; Gary, T.L.; Klassen, A.C. The built environment and obesity. Epidemiol. Rev. 2007, 29, 129–143, doi:10.1093/epirev/mxm009.
[2]
Davis, B.; Carpenter, C. Proximity of fast-food restaurants to schools and adolescent obesity. Am. J. Public Health 2009, 99, 505–510.
[3]
Powell, L.M.; Auld, M.C.; Chaloupka, F.J.; O’Malley, P.M.; Johnston, L.D. Associations between access to food stores and adolescent body mass index. Am. J. Prev. Med. 2007, 33, S301–S307.
[4]
Seliske, L.M.; Pickett, W.; Boyce, W.F.; Janssen, I. Association between the food retail environment surrounding schools and overweight in Canadian youth. Public Health Nutr. 2009, 12, 1384–1391.
[5]
Laska, M.N.; Hearst, M.O.; Forsyth, A.; Pasch, K.E.; Lytle, L. Neighbourhood food environments: Are they associated with adolescent dietary intake, food purchases and weight status? Public Health Nutr. 2010, 13, 1757–1763.
[6]
Bader, M.D.; Ailshire, J.A.; Morenoff, J.D.; House, J.S. Measurement of the local food environment: A comparison of existing data sources. Am. J. Epidemiol. 2010, 171, 609–617, doi:10.1093/aje/kwp419.
[7]
Cummins, S.; Macintyre, S. Are secondary data sources on the neighbourhood food environment accurate? Case-study in Glasgow, UK. Prev. Med. 2009, 49, 527–528, doi:10.1016/j.ypmed.2009.10.007.
[8]
Hosler, A.S.; Dharssi, A. Identifying retail food stores to evaluate the food environment. Am. J. Prev. Med. 2010, 39, 41–44, doi:10.1016/j.amepre.2010.03.006.
[9]
Lake, A.A.; Burgoine, T.; Greenhalgh, F.; Stamp, E.; Tyrrell, R. The foodscape: Classification and field validation of secondary data sources. Health Place 2010, 16, 666–673, doi:10.1016/j.healthplace.2010.02.004.
[10]
Liese, A.D.; Colabianchi, N.; Lamichhane, A.P.; Barnes, T.L.; Hibbert, J.D.; Porter, D.E.; Nichols, M.D.; Lawson, A.B. Validation of 3 food outlet databases: Completeness and geospatial accuracy in rural and urban food environments. Am. J. Epidemiol. 2010, 172, 1324–1333, doi:10.1093/aje/kwq292.
[11]
Paquet, C.; Daniel, M.; Kestens, Y.; Leger, K.; Gauvin, L. Field validation of listings of food stores and commercial physical activity establishments from secondary data. Int J. Behav. Nutr. Phys. Act 2008, 5.
[12]
Sharkey, J.R.; Horel, S. Neighborhood socioeconomic deprivation and minority composition are associated with better potential spatial access to the ground-truthed food environment in a large rural area. J. Nutr. 2008, 138, 620–627.
[13]
Statistics Canada. 2006 Census Dictionary; Catalogue No. 92-566-X. 2006. Available online: http://www12.statcan.gc.ca/census-recensement/2006/ref/dict/pdf/92-566-eng.pdf (accessed on October 2010).
[14]
The Yellow Pages. Available online: http://www.yellowpages.ca (accessed on March 2010).
[15]
Google Inc. Google Earth (Version 6.1.0.5001). 2010. Available online: http://earth.google.com (accessed on March 2010).
