Due to copyright issues, an electronic copy of the thesis must be ordered from the faculty. For the faculty to have time to process the order, the order must be received by the faculty at the latest 2 days before the public defence. Orders received later than 2 days before the defence will not be processed. After the public defence, please address any inquiries regarding the thesis to the candidate.
Trial Lecture – time and place
See Trial Lecture.
Adjudication committee
- First opponent: Associate professor Hille Suojalehto, Finnish Institute of Occupational Health,
- Second opponent: Senior consultant Lisa Aarhus, STAMI,
- Third member and chair of the evaluation committee: Professor Carl Tollef Solberg, University of Oslo
Chair of the Defence
Professor Knut Stavem, University of Oslo
Principal Supervisor
Associate Professor Anne Kristin Møller Fell, University of Oslo
Summary
Even though asthma is a complex multifactorial disease, a significant percentage of new-onset asthma in adults (25%) is associated with occupational exposure.
The aim of this thesis was to estimate the asthma incidence and to assess the associations between occupational exposure, new-onset asthma and asthma exacerbation. Furthermore, the aim was to characterize those who were lost to five-year follow-up and to analyze the impact of non-response on the exposure-outcome associations.
This thesis is part of a five-year follow-up study of the baseline cohort of the Telemark study. The data was obtained from a postal questionnaire distributed to participants in 2013 and 2018. The questionnaire included questions regarding occupational history, exposure at workplace, respiratory symptoms and physician-diagnosed asthma.
We found that new-onset asthma was associated with higher frequency of self-reported occupational exposure to vapor, gas, dust, and fumes (VGDF), and exposure to mold, damage due to moisture, and cold. When assessing associations with more objective measures of exposure (job exposure matrix) we observed that new-onset asthma was associated with accidental peak exposure to irritants.
Accidental peak exposure to irritants was also associated with severe asthma exacerbation. Participants who reported asthma exacerbation had an increased risk of job change, sick leave and reduced work ability.
Risk factors for non-participation were male gender, younger age, lower educational level, current smoking, respiratory symptoms and exposure to VGDF, sensitizers and irritants. Further analysis of the loss to follow-up group showed that our estimates were less likely to be affected by the loss of participants at follow-up.
In conclusion, this study found that both new-onset asthma and asthma exacerbation were associated with occupational exposure. The thesis implies that assessing loss to follow-up is of importance for the evaluation and the validity of the results.
Additional information
Contact the research support staff.