Table 3. The effect of herbicide use and other covariates on ADHD hospital discharges, showing the initial OLS screening for each predictor for 2008 and 2010 and all significant predictors in a two ways effects within model in R, adjusting for heteroskedasticity and serial correlation.
| Covariate | Linear Model (criteria variable for inclusion, p < .05) | Time and State Fixed Effects (2007–2010) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2008 | 2010 | |||||||||||
| N | r 2 | Estimate | Std Error | N | r 2 | Estimate | Std Error | N 1 a | Estimate | Std Error | ||
| Food/Industrial Use—Maize | — | — | — | — | — | — | — | — | 127 | 2.70E-02 | 0.013 * | |
| Pesticide | ||||||||||||
| Glyphosate | Amino Acid synthesis inhibitor | — | — | — | — | — | — | — | — | 127 | 5.54E-08 | 1.68e-08 ** |
| Atrazine | Photosystem II inhibitor | 31 | 0.04 | 6.98E-08 | 6.28E-08 | 32 | 0.04 | 6.92E-08 | 5.93E-08 | — | — | — |
| Clethodim | ACCase inhibitor | 31 | 0.03 | 1.11E-05 | 1.11E-05 | 32 | 0.02 | 5.96E-06 | 7.35E-06 | — | — | — |
| Halosulfuron | Acetolactate synthase inhibitor | 31 | 0.03 | -7.75E-05 | 7.82E-05 | 32 | 0.01 | -3.18E-05 | 6.12E-05 | — | — | — |
| Home Price Index | 31 | 0.09 | -4.41E-01 | 2.66E-01 | 32 | 0.02 | -2.84E-01 | 3.97E-01 | — | — | — | |
| Population | 31 | 0.17 | -5.41E-02 | 0.022* | 32 | 0.14 | -5.53E-02 | 0.02499* | 127 | -4.11e-01 | 2.81e-01 | |
| Health Care Access | 31 | 0.07 | -5.03E-02 | 3.35E-02 | 32 | 0.05 | -4.82E-02 | 3.81E-02 | — | — | — | |
| Precipitation Lag | 31 | 0.14 | 6.71E-01 | 0.3109* | 32 | 0.01 | 1.96E-01 | 3.96E-01 | 127 | 1.13e-02 | 4.50e-02 | |
** p < .01
* p < .05
a N 1 is the total number of state-time observations