Accuracy of residential geocoding in the Agricultural Health Study

Table 1 Distribution of positional error (meters) by geo-location data sources for Agricultural Health Study addresses in 14 counties in Iowa, overall and by rural status ^a

Positional error (m)
Geo-location data comparison	N	Min	Mean	SD	Median (IQR)	Max	Percent ≤100 m	Percent ≥1000 m
Overall
Address-matched vs. Rooftop	5064	4	312	956	90 (47–215)	15171	53	6
E911 vs. Rooftop	5064	7	62	83	39 (22–61)	1276	87	0.1
Rural ^a
Address-matched vs. Rooftop	3296	4	444	1159	147 (78–353)	15171	34	9
E911 vs. Rooftop	3296	11	83	93	51 (39–83)	1199	80	0.1
Non-rural
Address-matched vs. Rooftop	1768	6	66	151	45 (27–68)	4694	89	0.3
E911 vs. Rooftop	1768	7	23	35	19 (17–23)	1275	99	0.1

^aRural status was defined as a rooftop location outside of the U.S. Census 2000 Incorporated Places boundary.

ISSN: 1476-072X