Accuracy of city postal code coordinates as a proxy for location of residence

• Main Authors: Seidel Judy E, Faris Peter D, Waters Nigel M, Bow C Jennifer D, Galbraith P Diane, Knudtson Merril L, Ghali William A
• Format: Article
• Language: English
• Published: BMC 2004-03-01
• Series: International Journal of Health Geographics
• Subjects: Geographic Location; Postal Code; GIS (Geographical Information Systems)
• Online Access: http://www.ij-healthgeographics.com/content/3/1/5

<p>Abstract</p> <p>Background</p> <p>Health studies sometimes rely on postal code location as a proxy for the location of residence. This study compares the postal code location to that of the street address using a database from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH^©). Cardiac catheterization cases in an urban Canadian City were used for calendar year 1999. We determined location in meters for both the address (using the City of Calgary Street Network File in ArcView 3.2) and postal code location (using Statistic Canada's Postal Code Conversion File).</p> <p>Results</p> <p>The distance between the two estimates of location for each case were measured and it was found that 87.9% of the postal code locations were within 200 meters of the true address location (straight line distances) and 96.5% were within 500 meters of the address location (straight line distances).</p> <p>Conclusions</p> <p>We conclude that postal code locations are a reasonably accurate proxy for address location. However, there may be research questions for which a more accurate description of location is required.</p>