| Univariable model | Multivariable model | |||
|---|---|---|---|---|
| Characteristic | β coefficient (95% CI) | p value | β coefficient (95% CI) | p value |
| Geography | ||||
| Latitude of state centroid | 0.014 (0.0073 to 0.021) | < 0.001 | 0.014 (0.0075 to 0.021) | < 0.001 |
| Longitude of state centroid | 0.00049 (–0.00084 to 0.0018) | 0.5 | – | |
| Environment | – | |||
| % national wilderness (2000) | 0.00047 (–0.0041 to 0.0050) | 0.8 | – | |
| New housing permits, thousands (2002) | –0.00060 (–0.0017 to 0.00047) | 0.3 | – | |
| Demography | ||||
| % change in population between 1990 and 2000 censuses | –0.0016 (–0.0075 to 0.0042) | 0.6 | – | |
| Population density, thousands per km2 (2000) | 0.069 (–0.0050 to 0.14) | 0.07 | 0.070 (0.0049 to 0.14) | 0.04 |
| % rural residents (2000) | 0.00017 (–0.0025 to 0.0028) | 0.9 | – | |
| Politics and economy | ||||
| Log of per capita GDP (2000) | 0.19 (–0.022 to 0.41) | 0.08 | – | |
| Democrat- v. Republican-voting state (2004) | 0.10 (0.030 to 0.18) | 0.006 | – | |
| Per capita health spending per 100 population (2002) | 0.00025 (–0.00015 to 0.00065) | 0.2 | – | |
| Income inequality, Gini coefficient (1999) | –1.00 (–2.50 to 0.50) | 0.2 | – | |
Note: CI = confidence interval, GDP = gross domestic product.