Evaluation of associations between asthma exacerbations and distance to roadways using geocoded electronic health records data.

While the results were non-significant, the characteristics of the study sample - namely farther distance to roadways and generally good ambient environmental pollution may contribute to the lack of effect. Compared to previous studies, which often relied on self-reported measures, we were able to obtain a more objective assessment of outcomes. Overall, this work highlights the opportunity to use EHR data to study environmental impacts on disease.