Occupational risk factors for asthma exacerbation in adults: a five-year follow-up of the Norwegian Telemark study cohort.

Objectives: Asthma exacerbation due to occupational exposure is highly prevalent among adults with asthma. This study assessed the association between occupational risk factors and asthma exacerbation and estimated the impact of asthma exacerbations on job change, sick leave and work ability.

Methods: In a prospective study of respiratory health in Telemark, Norway, 1857 adult participants with physician-diagnosed asthma were invited to participate in a follow-up survey. Among those who responded, 740 were found eligible for this study. Participants were categorized into overall, mild, and severe asthma exacerbation groups based on self-reports of hospitalization, doctor or emergency visits for breathing difficulties, or increased or new use of lung medications. Logistic regression, adjusted for age, sex, and smoking, was used to assess associations between self-reported asthma exacerbation and exposure to VGDF, job exposure matrix (N-JEM) data, job change, sick leave, and work ability.

Results: Asthma exacerbation occurred in 140 (19%) responders; 83 had mild exacerbations and 57 severe exacerbations. Severe exacerbation was associated with daily VGDF exposure (OR 2.57, 95% CI 1.15-5.78) and accidental peak exposure to irritants (OR 4.62, 95% CI 1.13-18.85). Both overall and severe exacerbation were associated with job changes (OR 5.40, 1.26-5.65; OR 3.06, 1.16-8.07), sick leave (OR 1.94, 1.33-2.85; OR 2.78, 1.57-4.92), and reduced work ability (OR 1.61, 1.04-2.49; OR 2.17, 1.18-3.98).

Conclusion: Asthma exacerbation was associated with VGDF exposure and some N-JEM occupational exposures. Reducing workplace exposure may decrease job-change, sick leave, and improve work ability in individuals with asthma exacerbation.