Date of Award

Summer 7-26-2013

Degree Type


Degree Name

Master of Public Health (MPH)


Public Health

First Advisor

Dr. Kymberle Landrum Sterling

Second Advisor

Dr. Bruce Clement Perry

Third Advisor

Dr. Hatice Zahran



Background: Asthma is a chronic lung disease that inflames and narrows the airways. This results in recurrent episodes of coughing, wheezing, shortness of breath, and chest tightness. Although the causes of asthma are poorly understood, genetic and environmental factors have been implicated in the development and exacerbation of the disease. Among environmental risk factors, cigarette smoke is a well-known risk factor to trigger asthma symptoms. Exposure to secondhand smoke irritates the airways and may trigger an attack in adults with asthma. Smoke-free laws and regulations in the United States differ by state. The enforcement of smoke-free legislation has been related to asthma rates as it has been shown that they lead to a sustained drop in emergency hospital admission for asthma among adults. These laws and regulations are also necessary in reducing smoking rate and secondhand smoke exposure.

Objective: The purpose of this thesis is to examine the association between tobacco smoke rates and asthma status among adults at the national and state levels and to evaluate the effects of state smoke-free laws and regulations on tobacco smoking rate among adults with asthma.

Methods: The Centers for Disease Control and Prevention’s 2009–2010 Behavioral Risk Factor Surveillance System data was used for the analyses. SAS-callable SUDAAN (version 10.0.0, RTI International, NC) was utilized to account for the complex sampling design of the BRFSS, and sample weights were used to produce estimates that were generalizable to the state and U.S. adult population. In addition to calculating descriptive statistics, chi-square tests and multivariate logistic regression were used to test for group differences and association between variables of interest. State level smoking rates were ranked to identify states that are in the lower and upper 20th percentiles and compare them with states’ smoke-free laws and regulation status.

Results were considered significantly different if 95% confidence intervals (CIs) did not overlap or if statistical testing at p<0.05 was applicable.

Results: Asthma prevalence rates are higher among adults that smoke cigarettes (10.5%, [aPR] =1.2) compared to non-smokers (7.8%, [aPR] =1.0). Of the 869,519 adult respondents in the survey, 8.5% reported having asthma. Nearly one-fifth (17.2%) of adults without asthma smoked cigarettes, while (21.7 %) of adults with asthma smoked. Females (10.5%) had higher asthma prevalence rates than males (6.4%). Black persons (10.0%), persons of American Indian (13.0%) descent had higher, and those of Hispanic (6.7%) descent had lower asthma rates than white persons (8.6%). Adults with a high school education or less (9.1%) had higher asthma rates than those with an education level that was equivalent to a 4 year college or more (7.3%) , and those with low income (<$15,000) had higher rates (13.3%) than those with high income (6.8%). Percentage of male (23.4%) and females (20.7%) with asthma who smoke are higher than those that do not smoke (19.3% and 15.1%, respectively).

Asthma prevalence rates and smoking rates vary by geographic location. Smoking rates among adults with asthma was highest in the South (LA, AL, SC, TN, OK, MS, AR, WV, KY) and a couple of Midwest states (OH, IN,). Evaluating the association between the 2008 State of Tobacco Control Report and smoking rate among adults with asthma by state showed a statistically significant relationship between smoking rate among adults with asthma and smoke-free policy and regulation at the state and national level. On average, states with the lowest smoking rate among persons with asthma (smoking rates less than 20th percentile) had significantly higher smoke-free policy grades (mean grade [sd]=7.2 [1.99]) than states with a high smoking rate (smoking rate of 80th percentile or more) (mean grade [sd]=2.0 [2.00]) (p-value < 0.00001).

Conclusion: Although most U.S. state smoke-free policies and regulations are relatively new, it is evident that these laws are effective in promoting cessation among adults and reducing nonsmokers’ exposure to secondhand smoke. The study found that smoke-free laws may improve health by lowering asthma prevalence and smoking rates among adult smokers. Also, these policies in turn protect non-smokers from the harmful health effects of secondhand smoke.