On the wrong side of the tracts? Evaluating the accuracy of geocoding in public health research.
OBJECTIVE
This study sought to determine the accuracy of geocoding for public health databases.


METHODS
A test file of 70 addresses, 50 of which involved errors, was generated, and the file was geocoded to the census tract and block group levels by 4 commercial geocoding firms. Also, the "real world" accuracy of the best-performing firm was evaluated.


RESULTS
Accuracy rates in regard to geocoding of the test file ranged from 44% (95% confidence interval [CI] = 32%, 56%) to 84% (95% CI = 73%, 92%). The geocoding firm identified as having the best accuracy rate correctly geocoded 96% of the addresses obtained from the public health databases.


CONCLUSIONS
Public health studies involving geocoded databases should evaluate and report on methods used to verify accuracy.
Krieger
N
N
Department of Health and Social Behavior, Harvard School of Public Health, 677 Huntington Ave, Boston, MA 02115, USA. nkrieger@hsph.harvard.edu
Waterman
P
P
Lemieux
K
K
Zierler
S
S
Hogan
J W
JW
D000043:Abstracting and Indexing / Q000191:economics / Q000592:standards*; D015982:Bias; D019352:Censuses; D003365:Costs and Cost Analysis; D003625:Data Collection / Q000191:economics / Q000592:standards; D016208:Databases, Factual / Q000191:economics / Q000592:standards*; D004812:Epidemiologic Methods; D006801:Humans; D008377:Maps as Topic; D009511:New England; D011159:Population Surveillance / Q000379:methods; D011634:Public Health; D012111:Residence Characteristics / Q000706:statistics & numerical data*; D013997:Time Factors