Table 1: State-level characteristics associated with trends in Lyme disease incidence in the United States from 1993 to 2007.
| 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.