Work-related asthma in the USA: nationally representative estimates with extended follow-up

We studied the associations of working in occupations with high asthma trigger exposures with the prevalence and incidence of asthma, and with ever reporting an asthma diagnosis throughout working life.

We used the nationally representative Panel Study of Income Dynamics (1968-2015; n=13 957; 205 498 person-years), with annual reports of occupation and asthma diagnoses across 48 years. We compared asthma outcomes in occupations likely to have asthma trigger exposures with those in occupations with limited trigger exposures. We estimated the prevalence ratios and the incidence risk ratios using log-binomial regression adjusted for age, sex, race/ethnicity, education, and current and past atopy and smoking, and accounting for the survey design and sampling weights. We calculated the attributable risk fractions and population attributable risks, and used multinomial logistic Markov models and microsimulation to estimate the percentage of people ever diagnosed with asthma during working life.

The adjusted prevalence ratio comparing high-risk occupations with low-risk was 4.1 (95% CI 3.5 to 4.8); the adjusted risk ratio was 2.6 (CI 1.8 to 3.9). The attributable risk was 16.7% (CI 8.5 to 23.6); the population attributable risk was 11.3% (CI 5.0 to 17.2). In microsimulations, 14.9% (CI 13.4 to 16.3) with low trigger exposure risk reported asthma at least once, ages 18-65, compared with 23.9% (CI 22.3 to 26.0) with high exposure risk.

Adults were more than twice as likely to report a new asthma diagnosis if their occupation involved asthma triggers. Work exposures to asthma triggers may cause or aggravate about 11% of all adult asthma and increase the risk of work-life asthma by 60%.