Associations of Herbs and Nonvitamin Dietary Supplements Use with Clinical Outcomes Among Adult and Pediatric Patients with Asthma in the United States.

BACKGROUND: Herbs and nonvitamin dietary supplements (NVDS) have been commonly used among patients with asthma, yet evidence of their impact on patients' clinical outcomes is limited.

OBJECTIVE: This study examined the associations of herbs and NVDS use with asthma episodes and asthma-related emergency department (ED) visits among US adults and pediatric patients with asthma.

METHODS: A cross-sectional analysis of the 2012 National Health Interview Survey data included 2,930 US adults and 1923 children with self-reported asthma. We estimated the prevalence and type of herbs and/or NVDS use and identified factors associated with their use. We then used multivariable logistic regression models to examine the associations between these supplemental medications use and asthma outcomes, controlling for patient-related covariates. All results were weighted to represent national estimates.

RESULTS: Approximately 7.20% of American children and 21.17% of adults with asthma used herbs and/or NVDS in 2012. Herb and/or NVDS users were more likely to be female, non-Hispanic white, living in the West region, having higher family income, and having comorbidities compared with nonusers. Herbs and/or NVDS use was associated with lower likelihood of having asthma-related ED visit (adjusted odds ratio = 0.48; 95% confidence interval: 0.31, 0.75) among adult patients with asthma, but not for pediatric patients with asthma. No association between herbs and/or NVDS use and having an asthma episode was observed in either adults or children.

CONCLUSIONS: This study found high prevalence of herbs and/or NVDS use among US patients with asthma. Potential benefit of these supplemental medications use on asthma-related ED visits might exist for adult patients with asthma.