Measuring Geocode Location Error in Atlanta
Author Information
Author(s): Matthew J Strickland, Csaba Siffel, Bennett R Gardner, Alissa K Berzen, Adolfo Correa
Primary Institution: Centers for Disease Control and Prevention
Hypothesis
How accurate are geocodes for maternal addresses in birth defect cases?
Conclusion
Geocode location uncertainty can be estimated using tax parcel databases in a GIS, with median errors being less than 100 meters.
Supporting Evidence
- Median location error was less than 100 meters for both OHIP and commercial vendor geocodes.
- Location error was approximately 35% larger in Gwinnett County compared to Fulton County.
- The median percentage of geocodes resolving into incorrect census tracts ranged between 4.5% and 5.3%.
Takeaway
This study looked at how accurate the addresses of babies with birth defects are. It found that the addresses are usually pretty close, but sometimes they can be off by a bit.
Methodology
The study used GIS methods to assess geocode accuracy by comparing maternal addresses to tax parcel datasets.
Potential Biases
Selection bias may occur if the probability of a geocode being missing varies across different areas.
Limitations
The study may have underestimated the true distribution of geocode location error due to exclusion of discordant addresses.
Participant Demographics
Infants and fetuses with birth defects delivered between 1994 and 2002 in Fulton and Gwinnett County.
Digital Object Identifier (DOI)
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