Table 1.
Descriptive statistics for SARS-CoV-2 infection rates, SES and demographic factors, pre-existing chronic disease factors, and green space factors in the USA’s 135 most urbanized counties.
| Variable Categories | Variables | Min | Max | Mean | SD | Unit or Formula | VIF Test |
|---|---|---|---|---|---|---|---|
| Infection outcomes | Black infection rate | 91.6 | 2514.8 | 987.9 | 583.7 | Cases per 100 k | N/A |
| White infection rate | 29.1 | 2486.2 | 496.8 | 336.2 | Cases per 100 k | N/A | |
| Difference in black–white infection rates | −367.9 | 1874.2 | 491.1 | 447.3 | Cases per 100 k | N/A | |
| SES and demographic factors | Population density | 27.8 | 19625.8 | 1003.2 | 2356.6 | Persons per square kilometer | Retained |
| Female population ratio | 0.479 | 0.533 | 0.511 | 0.010 | Female/ total population | Retained | |
| Difference in black–white population | −0.878 | 0.481 | −0.407 | 0.274 | Black-to-white population ratio | Retained | |
| Difference in black–white older adults | −0.201 | 0.050 | −0.078 | 0.041 | Black older adults-to-white older adults population ratio | Retained | |
| Household size | 2.1 | 3.3 | 2.6 | 0.3 | Persons per household | Retained | |
| Households with broadband | 0.666 | 0.917 | 0.818 | 0.056 | Ratio | Retained | |
| Median household income | 38085 | 117374 | 62484 | 16126 | USD | Retained | |
| Healthcare receipts | 222956 | 2129326 | 771836 | 310816 | 1000 USD per 100 k | Retained | |
| Number of firms | 5000 | 19365 | 8595 | 2076 | Number of firms per 100 k | Retained | |
| Housing value | 95600 | 1009500 | 265468 | 181861 | USD | Removed | |
| Rate of high school graduate or higher | 0.698 | 0.959 | 0.882 | 0.049 | Ratio | Removed | |
| Poverty rate | 0.042 | 0.273 | 0.139 | 0.046 | Ratio | Removed | |
| Travel time to work | 15.50 | 44.80 | 25.61 | 5.50 | Minutes | Removed | |
| Employment rate | 18309 | 139791 | 43397 | 15190 | Employment per 100 k | Removed | |
| Pre-existing chronic disease factors | Coronary heart disease death rate | 45.3 | 144.9 | 85.1 | 22.0 | Cases per 100 k | Retained |
| Heart failure death rate | 34.4 | 170.3 | 89.1 | 24.6 | Cases per 100 k | Retained | |
| Diagnosed diabetes rate | 0.046 | 0.140 | 0.090 | 0.018 | Cases/total population | Retained | |
| Obesity rate | 0.147 | 0.401 | 0.284 | 0.057 | Cases/total population | Removed | |
| Green space factors | Developed open space | 0.005 | 0.289 | 0.102 | 0.064 | Developed open space area/ county area | Retained |
| Forest | 0.001 | 0.738 | 0.172 | 0.163 | Forest area/county area | Retained | |
| Shrub and scrub | 0.000 | 0.829 | 0.082 | 0.177 | Shrub and scrub area/county area | Retained | |
| Grassland and herbaceous | 0.001 | 0.498 | 0.061 | 0.093 | Grassland and herbaceous area/county area | Retained | |
| Pasture and hay | 0.000 | 0.485 | 0.069 | 0.092 | Pasture and hay area/county area | Retained | |
| Cultivated crops | 0.000 | 0.719 | 0.124 | 0.168 | Cultivated crops area/county area | Retained | |
| Woody wetlands | 0.000 | 0.453 | 0.050 | 0.078 | Woody wetlands area/county area | Retained | |
| Emergent herbaceous wetlands | 0.000 | 0.605 | 0.026 | 0.080 | Emergent herbaceous wetlands area/county area | Retained | |
| Built-up area factors | Developed Low Intensity | 0.008 | 0.414 | 0.118 | 0.086 | Developed Low Intensity area/county area | Removed |
| Developed Medium Intensity | 0.006 | 0.367 | 0.093 | 0.085 | Developed Medium Intensity/county area | Removed | |
| Developed High Intensity | 0.001 | 0.505 | 0.052 | 0.081 | Developed High Intensity/county area | Removed |
Note: Min = minimum; Max = maximum; SD = standard deviation; Per 100 k = Per 100,000 population; USD = United States Dollar.