# Table 2 Bias and error in determining children at-risk based on proximity to major roads in Orange County, Florida.

Buffer Radius (m) Number of children within buffer zone Comparison measures
Parcels Street Parcels yes/Street yes Parcels yes/Street no Parcel no/Street yes Parcel no/Street no Sensitivity (%)1 Specificity (%)2 Odds Ratio (95% CI)3
50 meters 391 1413 151 240 1262 103212 39 99 0.28 (0.25 – 0.31)
100 meters 2090 2851 1392 698 1459 101316 67 99 0.73 (0.69 – 0.77)
150 meters 4717 5276 3899 818 1377 98771 83 99 0.89 (0.85 – 0.93)
250 meters 10729 10945 9704 1025 1241 92895 90 99 0.98 (0.95 – 1.01)
500 meters 26347 26597 25201 1146 1396 77122 96 98 0.99 (0.97 – 1.01)
1000 meters 54500 54614 53838 662 776 49589 99 98 01.00 (0.980 – 1.01)
1. 1 Sensitivity is the percentage of parcel geocoded children residing within the buffer zone that were correctly classified using street geocoding.
2. 2 Specificity is the percentage of parcel geocoded children residing outside the buffer zone that were correctly classified using street geocoding.
3. 3 The odds-ratio is determined by comparing the parcel and street geocoded populations. The odds-ratio represents the odds that parcel geocoded addreses are within a given buffer radius, given that street-geocoded locations for the same address fall inside vs. outside the buffer radius. A value less than 1 indicates that the odds for the parcel geocoded population residing within the buffer radius is lower than for the street geocoded population