Background: Secondhand tobacco smoke increases the risk for the development and increasing severity of asthma among adults and children. Reducing exposure to secondhand smoke decreases symptomatic exacerbations among patients with asthma. Emergency department (ED) visits for asthma were assessed before and after the implementation of smoke-free legislation in Lexington-Fayette County, Ky. Objective: To evaluate the effects of a smoke-free law on the rate of ED visits for asthma. Methods: The study included ED visits for asthma from 4 hospitals in Lexington-Fayette County, Ky. Age-adjusted rates of asthma ED visits were determined. Poisson regression analysis of ED visits from January 1, 2001, to December 31, 2006 compared the ED visit rates between prelaw and postlaw, adjusting for seasonality, secular trends over time, and differences among demographic subgroups. The actual rates were graphed with the Poisson curve showing the rates predicted by the model. A second prediction curve was generated to show the projected rates in the postlaw period if the law had not been implemented. Results: Adjusting for seasonality, secular trends, and demographic characteristics, ED visits for asthma declined 22% from prelaw to postlaw (P < .0001; 95% CI, 14% to 29%). The rate of decline was 24% in adults age 20 years and older (P < .0001), whereas the decrease among children 19 years or younger was 18% (P = .01). Conclusion: Although this study did not establish causation, the smoke-free law was associated with fewer asthma ED visits among both children and adults, with a more significant decline among adults.

Original languageEnglish
Pages (from-to)537-541.e3
JournalJournal of Allergy and Clinical Immunology
Issue number3
StatePublished - Sep 2008

Bibliographical note

Funding Information:
Supported by the Flight Attendant Medical Research Institute.

Funding Information:
Disclosure of potential conflict of interest: E. J. Hahn receives grant support from the Flight Attendant Medical Research Institute. D. K. Moser receives grant support from the National Institutes of Health–National Institute of Nursing Research and the National Institutes of Health–Nation Heart, Lung, and Blood Institute. D. Mannino is on the advisory board for GlaxoSmithKline and Pfizer and the Data Safety Monitoring Board for Boehringer-Ingelheim; receives grant support from GlaxoSmithKline, Pfizer, and Novartis; and has provided legal consultation or expert witness testimony in cases related to secondhand smoke and diacetyl exposure. M. K. Rayens receives grant support from the Flight Attendant Medical Research Institute. The rest of the authors have declared that they have no conflict of interest.


  • Asthma
  • asthma exacerbation
  • asthma health outcomes
  • asthma triggers
  • environmental tobacco smoke
  • secondhand tobacco smoke
  • smoke-free legislation

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology


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