Race differences in the associations of substance/drug use with the prevalence of asthma in US adults: Results from the 2011 The National Survey on Drug Use and Health data

Background: Drug or substance use is a known risk factor for asthma and asthmatic complications. However, racial differences of this association have not well been evaluated. We examined the association and racial differences in alcohol and substance use, and asthma.

Methods: Analyses of 38,623 respondents from the 2011 National Survey on Drug Use and Health (NSDUH) data was conducted. The NSDUH is a survey of the civilian non-institutionalized individuals aged ≥12 years in the US to provide annual population estimates of substance use and health. The survey is estimated to cover about 98% of the total population within this age bracket .Weighted response rates for Hispanic/Latino (HL), African Americans (AA), Non-Hispanic Whites (Whites) and Multiple races (Other races) in 2011 were approximately 78%, 80%, 73% and 68% respectively. Weighted univariate and multiple logistic regressions were used to estimate associations between the selected predictors and asthma. Further weighted multiple regression analyses were conducted separately for 24,421 Whites, 4,931 African-Americans (AA), 5,976 Hispanics/Latinos, and 3,295 Other Races. We examined seven drug use variables in each model, and adjusted for age, gender, income and educational level.  All analyses were conducted with SAS statistical software, version 9.2 (SAS Institute, Cary, NC, USA).

Results: Prevalence of asthma was 5.8%, 6.2%, 6.5%, and 6.7% in Whites, AA, Other races, and Hispanics/Latinos, respectively. Females, early initiation of alcohol consumption, and illicit drug use (IDU) showed significantly increased odds with asthma (OR=1.68, 1.22 & 1.40, respectively) in all races combined. Alcohol consumption before age 18 was associated in only AAs (OR=2.0, 95%CI, 1.20 – 3.35) and Hispanics (OR=1.76, 95% CI, 1.05-2.96)); marijuana use prior to 18 years was associated in Hispanics only (OR=1.98, 95% CI, 1.09-3.59). Past year marijuana and IDU use were associated in AAs (OR=1.59, 95% CI 1.02-2.50) and Hispanics (OR=2.37, 95% CI 1.26-4.46), respectively. In other races, there was nearly a twofold increased odds of asthma (OR=2.84, 95% CI, 1.31-6.16) for past year alcohol use.

Conclusion: Our results confirm racial differences in the association between substance/drug use and asthma. Our findings provide a further insight into racial differences in asthma, and the need to explore race-specific asthma risk factors in a population based study.