The Association between Adult Self-reported Asthma & Potential
Exposures to Asthma Triggers in Virginia Workplaces:
An Ecological
Study
Jeanette Bowman
Advisor: May Kennedy, PhD., MPH
Preceptor: Michele M. Monti, MS
Introduction: Work-related asthma (WRA) is thought
to be the most common occupational lung disease in the U.S., but there is
no standard case definition of WRA. Most states, including Virginia,
do not require WRA diagnoses to be reported to health departments. At
present, there is too little epidemiological data on WRA in Virginia to direct
public health planning efforts.
Objectives: The first objective of this study was to estimate
potential exposure to workplace asthma triggers in each of Virginia’s
35 health districts. The second objective was to examine associations
at the health district level between workplace asthma triggers, other asthma
risk factors, and asthma prevalence in Virginia. The third objective
was to identify the specific health districts in which workers face the highest
risk of WRA.
Methods: This ecological study required merging three
datasets. Information on weight, age, race/ethnicity, income, gender,
and histories of asthma diagnosis and smoking was obtained from the Behavioral
Risk Factor Surveillance System (BRFSS) and aggregated at the health district
level. Information from the Virginia Employment Commission on the location,
industry, and number of employees of each business in the state was combined
with data on the asthma triggers found nationwide in specific industries
to calculate estimates of potential exposure to WRA triggers in each health
district. Descriptive, correlational and multiple regression analyses
were conducted, and health districts were sorted by asthma prevalence, or
number of workplace triggers, or trigger-based multivariate models of WRA
risk.
Results: On average, there are 50,l04 employees potentially
exposed to five or more asthma triggers in workplaces per health district. The
number of ever-diagnosed adult asthmatics was highly correlated with the number
of workplace asthma triggers in a health district, as well as with all demographic
and behavioral risk factors. A linear regression model including
number of workplace triggers, number of obese adults, and number of adults
with incomes below 200% of poverty accounted for 84% of the variance in health
district asthma prevalence. There was little overlap (2 health districts)
between the set of highest-risk health districts identified by this model and
the set identified by a sort on asthma prevalence alone.
Conclusion: The findings of this exploratory ecological
analysis suggest that the number of asthma cases in a health district may be
an insufficient indicator of health district risk of WRA. Additional
WRA surveillance and epidemiological research on WRA may be warranted in the
health districts shown in this study to be at highest risk of the disease.
