Methods: This study was approved by the Allegheny Singer Research Institute-Allegheny Health Network Institutional Review Board. Retrospective analysis of emergency department (ED) visits to the healthcare system was conducted from 07/01/2008 to 06/30/2013 to identify primary discharge diagnoses for acute exacerbations of respiratory diseases. Corresponding EPA air quality index (AQI) data was downloaded. F test with stepwise regression was used to evaluate the significance of OAP levels on day of ED visit and mean exposure over the previous week.
Results: 67,898 visits were included (mean + SD age of 40.3 + 25.2 years, 25.6% African American, 59.6% female). There was a direct association between levels of nitrogen dioxide (p<0.001) levels on both day of and week prior to ED visit for acute exacerbations of respiratory diseases. There was no significant association between ozone, PM2.5, carbon monoxide, sulfur dioxide or lead and ED visits.
Conclusions: Elevations of nitrogen dioxide were retrospectively associated with ED visits for acute exacerbations of respiratory diseases. Future efforts need to disseminate these results to local public health officials and ultimately improve health outcomes.