An ecological study on childhood autism

Table 2 Final general linear model showing significant predictors of autism and interaction terms (the analysis include the outlier county from Oregon)

Term	Coefficient	T statistic	p-value
Constant	0.546	46.12	<0.001
State of Washington (Reference State)
California	−0.155	−7.53	<0.001
Oregon	0.215	10.63	<0.001
% Surface drinking water	0.005	0.45	0.654
Annual Suicide rate	0.035	2.71	0.008
Average annual unemployment rate (1990,1995, and 2000)	−0.026	−2.37	0.020
Annual Precipitation	0.035	2.71	0.008
EPA Neurological Disease Risk	0.026	2.28	0.025
Heating Degree Days (HDD)	−0.067	−4.35	<0.001
EPA Neurological Disease Risk X HDD (interaction)	−0.040	−2.19	0.031
Precipitation X % Surface drinking water (interaction)	0.025	2.13	0.035

The adjusted R² for the model was 0.724. We used standardized explanatory variables in our model to enable comparison of coefficients.

ISSN: 1476-072X