Elevated chronic bronchitis diagnosis risk among women in a local emergency department patient population associated with the 2012 heatwave and drought in Douglas county, NE USA.

Background: Concerns about global climate change force local public health agencies to assess potential local disease risk.

Objective: Determine if risk of an emergency department chronic bronchitis diagnosis in Douglas County, NE, was higher during the 2012 heatwave compared to the same calendar period in 2011.

Methods: Retrospective, observational, case-control design selecting subjects from 2011 and 2012 emergency department (ED) admissions. Risk was estimated by conditional logistic regression.

Results: The odds of an ED chronic bronchitis diagnosis among females was 3.77 (95% CI =1.37-10.21) times higher during the 2012 risk period compared to females admitted to the ED during the 2011 risk period. Chronic bronchitis ED diagnosis odds were 1.05 (95%CI=1.04 - 1.06) times higher for each year of age. ED, gender, and race modified the risk (i.e., effect). The overall chronic bronchitis ED risk estimate was 1.61 (95%CI=0.81 - 3.21) times higher during the 2012 risk period compared to the 2011 risk period. The mean ambient absolute humidity upon admission was 11.44 gr/m (95%CI; 10.40 - 12.47) among chronic bronchitis cases and 12.67 gr/m (95%CI; 12.63 - 12.71) among controls.

Conclusion: The odds of ED chronic bronchitis diagnosis was higher among female subjects admitted during the 2012 risk period compared to females admitted during the 2011 risk period.  Age also increased chronic bronchitis ED diagnosis risk among 2012 risk period admissions compared to 2011 risk period admissions.