Table 2.
Distribution of contextual variables of BetaGene study participants collected from U.S. Bureau of Census 2000 block group and U.S. Postal Service ZIP code data
| Variable | n | Mean | Median | Inter-quartile Range |
|---|---|---|---|---|
| Median household income (US $) a | 1173 | 38705 | 36660 | (28480 – 46786) |
| Proportions of households below federally designated poverty rate a | 1173 | 0.22 | 0.21 | (0.12 – 0.29) |
| Proportions of adult who are unemployed a | 1173 | 0.06 | 0.05 | (0.04 – 0.07) |
| Proportion of respondents over age 25 with highest attained education a | ||||
| No education | 1173 | 0.07 | 0.07 | (0.03 – 0.11) |
| Lower than or equal to high school | 1167 | 18.72 | 5.86 | (2.43 – 12.63) |
| Some college or technical school | 1173 | 0.23 | 0.22 | (0.14 – 0.31) |
| More than 4 years of college | 1173 | 0.11 | 0.08 | (0.04 – 0.15) |
| Crime Index b | 1173 | 123 | 120 | (89 – 152) |
| Park or recreation areas (km2) b | 1173 | 0.015 | 0 | (0 – 0.017) |
| Number of fast food restaurants b | 1173 | 0.49 | 0 | (0 – 1) |
| Number of grocery stores b | 1173 | 1.72 | 1 | (0 – 2) |
a
Different GIS tools (intersect, dissolve and calculate field) were applied to calculate the proportion of the census block groups that fell within each of the 300 m buffers for each of the geocoded addresses.
b
GIS buffer tool was used to create 500 m buffer for each geocoded addresses.