Evaluating Cigarette Smoking as a Risk Factor for Asthma in Virginia
Adults
CORY MCGILL
Advisor: Tilahun Adera M.P.H, Ph.D
Preceptor: Gerges Seifen M.P.H, M.B.B.S.
Objective: There is currently limited and inconclusive research on the association between cigarette smoking and the risk of asthma among adults. This study examines the association between cigarette smoking and the prevalence of adult diagnosed asthma. The study also seeks to determine the prevalences of smoking and asthma amongst various sociodemographic factors such as age, sex, race, income, marital status, and educational attainment in the Virginia population.
Methods: The sample data was collected by a non-truncated random-digit dialing telephone survey of the civilian, non institutionalized, adult (18 years of age or older) population in Virginia. Titled, the Virginia Behavioral Risk Factor Surveillance System, Virginia BRFSS, the state survey is coordinated nationwide by the Centers for Disease Control, and Prevention and is coordinated locally with the Virginia Department of Health, Office of Family Health Services. In order to attain adequate sample size, we combined relevant variables on smoking and asthma from 2000 and 2001 Virginia BRFSS into a comprehensive file and transferred these relevant variables to the statistical software SPSS. Prevalence estimates for sociodemographic factors were calculated for both smokers and asthmatics using SPSS Statistical Software and Epi Info 6.x Stat-Calc.. Crude risk estimates were calculated for all risk factors for asthma using the software. In order to determine the relationship between cigarette smoking and asthma, adjusted risk estimates were computed using suspected confounders as covariates.
Results: Analyzing the demographics of the study population, the greatest prevalence of subjects were found within the 35-44 age group, 24.2%, with about a 3% decrease in higher and lower age groups. Three-fourths, 75.9%, of the population was ”White Non-Hispanic,” while the other majority was “Blacks Non-Hispanics,” 16.0%. The results showed 10.8% of respondents having asthma and about a half, 47.2%, having smoked 100 cigarettes in their lifetime. Among persons having smoked 100 cigarettes in their lifetime, we found the highest prevalence in the “55-64” age group at 56.6% and a decrease with decreasing age groups. “White Non-Hispanics,” were shown to have greater prevalence of smokers compared to the other groups, 48.6% vs. 41.5% for “Black Non-Hispanic,” and 45.3% for “Hispanic-Others.” Regarding gender, women had higher odds of being diagnosed with asthma than men, (OR 1.5;95% CI – 1.2,1.8). Those with income “less than $15,000 ,” had the highest odds of being diagnosed with asthma, (OR 1.6;95%CI – 1.0,2.5), compared to the referent group of “$20,000-$24,999.” Considering marital status, members of “an unmarried couple” and those who are “separated “had higher risks for asthma, (OR 1.8;95%CI – 1.2,3.2) and (OR 1.5;95%CI – 1.0,2.6) respectively of the marital status groups. The crude risk of asthma among those reporting “having smoked at least 100 cigarettes” was higher than those reporting the opposite, (OR 1.2;95%CI – 1.0,1.5). After adjustment, considering age, race, education, income, marital status, and sex, the risk showed no change. The only change among the variables after adjustment was that those on the extreme of income, now showed a significance for being diagnosed with asthma, (OR 1.6;95%CI – 1.0,2.6) for those earning “less than $15,000” and (OR 1.5;95%CI – 1.2,1.9) for those earning $75,000 or more.
Conclusion: Among Virginia Adults, smokers tended to be 18 to 24 year olds, male, and of lower educational attainment and income. Asthmatics tended to be female, age 18 to 24, and on the extremities of income. Cigarette smoking appears to be an independent risk factor for asthma prevalence among adults in Virginia. Consequently, smoking cessation policies should target these populations shown at risk for smoking as well as the asthma population, as the disorders may be linke
